feat: v0.3.0 Persistent + Z-Tiers + Input-Block

Layer z_tiers (hud/normal/top), persistent windows, and input_block
routing (none/self/all) on top of v0.2.0's multi-active + layout-slot
model. Render iterates per-tier (hud->normal->top); input dispatch
iterates reverse (top->hud, within-tier reverse-open-order); modal
input_block='all' swallows misses. Persistent windows open at
register-time and are exempt from arg-less close() (so ESC and default
triggers cannot dismiss persistent toolbars/HUDs).

Adds chromeless=true opt (suppresses panel-lib's own decoration so
in-game HUD widgets like map-editor's toolbar/layers/palette can paint
their own visual style over the full widget bounds).

Adds public panel.point_in_any_panel(x, y) — module-side canvas-click
gate that returns true if (x, y) falls within any open panel's
bounds. Modules read input directly via engine.input.*; they can use
this helper to skip canvas-paint when the click landed on a panel
widget area.

README.md

@@ -1,20 +1,24 @@
 # lib-core.panel
 
-Generic overlay-panel framework. v0.2.0 supports multiple panels open at
+Generic overlay-panel framework. v0.3.0 layers **z-tiers** (hud / normal
-the same time with 11 named layout-slot templates + custom-fn hook for
+/ top), **persistent windows**, and **input-block routing** (none / self
-bespoke positioning. Handles input dispatch (mouse click + wheel,
+/ all) on top of v0.2.0's multi-active model with 11 named layout-slot
-edge-detected with reverse-open-order hit-test), renders titled panel
+templates + custom-fn hook. Render iterates per-tier (hud → normal →
-overlays, and supports a context-menu layer on top. Designed as the glue
+top); input dispatch iterates reverse (top → hud, within-tier reverse
-layer between game modules and the engine render/input surfaces.
+open-order); modal `input_block="all"` swallows misses.
 
 The single-active model from v0.1.1 is preserved as a backward-
 compatibility shim — `panel.open(id)`, `panel.close()`, `panel.is_open()`
-without an id-arg keep their old semantics.
+without an id-arg keep their old semantics. v0.3.0 additionally makes
+`panel.close()` (no arg) a **no-op** when the focused window is
+`persistent=true` (so ESC-equivalents cannot dismiss persistent
+toolbars/HUDs); use `panel.close(id)` for explicit modder-controlled
+close.
 
-**Version:** 0.2.0
+**Version:** 0.3.0
 **Lib-ID:** lib-core.panel
 **Requires:** engine.render.*, engine.input.*, lib-core.input (lazy, for default-trigger)
-**Tags:** panel, overlay, ui, input, context-menu
+**Tags:** panel, overlay, ui, input, context-menu, window-manager
 
 ## Topology
 
@@ -31,23 +35,36 @@ graph LR
 ```
 <!-- topology:end -->
 
-## Scope (v0.2.0)
+## Scope (v0.3.0)
 
-v0.2.0 ships multi-active panels with layout-slot positioning,
+v0.3.0 layers z-tiers + persistent + input-block on top of v0.2.0's
-preserving full backward-compatibility with v0.1.1's single-active
+multi-active model, fully backward-compatible with v0.2.0 and v0.1.1
-callers via shim semantics. The lib is the generic UI-Framework
+callers. The lib is the generic UI-Framework substrate — domain-free
-substrate — domain-free per ADR-0001/ADR-0049, consumed by Display-
+per ADR-0001/ADR-0049, consumed by Display-Libs (inventory-list-
-Libs (inventory-list-display, crafting-display, notify-display) and
+display, crafting-display, notify-display) and modules (vagrant-
-modules (vagrant-skeleton).
+skeleton, map-editor).
 
-### Supported (v0.2.0)
+### Supported (v0.3.0)
 
-- Multi-active panels: multiple windows open simultaneously, each
+- **Z-tiers**: render order hud → normal → top. Input dispatch reverse
-  rendered + hit-tested independently.
+  (top → hud, within-tier reverse open-order).
-- 11 layout-slot templates (center, left, right, top, bottom, four
+- **Persistent windows**: `opts.persistent=true` auto-opens at register-
-  corners, left-half, right-half) for common positioning.
+  time. Arg-less `panel.close()` becomes no-op when focused is
-- Custom layout-fn hook `function(sw, sh) -> {x,y,w,h}` for bespoke
+  persistent (so ESC/default-trigger cannot dismiss a persistent
-  positioning (HUD elements, status displays, custom tool UIs).
+  toolbar/HUD). Explicit `panel.close(id)` still closes persistent.
+- **Input-block routing**: `opts.input_block` = `"none"` (skip hit-test
+  entirely — HUD passes clicks through), `"self"` (hit-test own bounds;
+  miss falls through to next window), `"all"` (modal — hit-test self;
+  miss is swallowed, never reaches game-layer). Defaults per tier:
+  hud→none, normal→self, top→all.
+- **Public `panel.point_in_any_panel(x, y)`**: helper for module-side
+  canvas-click logic — returns true if (x,y) falls within any open
+  panel's bounds. Useful for modules that read input directly via
+  `engine.input.*` and want to skip canvas-paint when the click landed
+  inside a panel widget.
+- Multi-active panels: multiple windows open simultaneously (unchanged
+  from v0.2.0).
+- 11 layout-slot templates + custom-fn hook (unchanged).
 - Bw-Compat-Shim: v0.1.1 `register(id, widget)` ohne opts works
   unchanged; `close()`/`is_open()` ohne arg map to focused = last-
   opened.
@@ -55,13 +72,6 @@ modules (vagrant-skeleton).
 - Context-menu via `show_context_menu` (unchanged).
 - Default-trigger key-binding via `bind_default_trigger` (unchanged).
 
-### Deferred (v0.3.0+)
-
-- Z-order tiers (hud / normal / top) for layered rendering.
-- Persistent windows (always-open, exempt from ESC-close).
-- Input-block modes (none/self/all) for pass-through vs modal capture.
-- Map-editor-style multi-region UI as first-class persistent widgets.
-
 ### Deferred (v0.4.0+)
 
 - Click-to-focus and explicit focus()/raise()/lower() API.
@@ -83,7 +93,22 @@ modules (vagrant-skeleton).
 
 **Syntax:** `panel.register(widget_id: string, widget_def: table, opts?: table) -> void`
 
-`opts` is optional. Accepted keys: `layout` (slot-name string or `function(sw, sh) -> {x,y,w,h}`; defaults to `"center"`) and `z_tier` (`"normal"`; v0.2.0 only the normal tier is exposed). See the [Multi-Active + Layout-Slots](#v020--multi-active--layout-slots) section below for the full slot table.
+`opts` is optional. Accepted keys:
+- `layout` — slot-name string, custom `function(sw, sh) -> {x,y,w,h}`, or
+  `nil` (defaults to `"center"`). See the [Layout-Slots](#layout-slots)
+  table.
+- `z_tier` — `"hud"` | `"normal"` (default) | `"top"`. Controls render
+  order (hud → normal → top) and hit-test order (top → normal → hud).
+- `persistent` — `bool` (default `false`). If true, the window is open
+  from the moment of registration and is exempt from arg-less
+  `panel.close()` (modder must close explicitly with `close(id)`).
+- `input_block` — `"none"` | `"self"` | `"all"`. Defaults per tier:
+  hud→`"none"`, normal→`"self"`, top→`"all"`. See [Input-Block](#input-block-routing-v030).
+- `chromeless` — `bool` (default `false`). If true, panel-lib skips its
+  own chrome (background, border, title-bar, close-X). The widget gets
+  the FULL panel bounds as `ctx.bounds` (no title-bar inset) and must
+  render its own background/border. Intended for persistent HUD widgets
+  (toolbars, layer-pickers, palettes) that have their own visual style.
 
 **Example:**
 ```lua
@@ -138,12 +163,39 @@ below for the migration recipe.
 
 **Syntax:** `panel.close(widget_id?: string) -> void`
 
-With `widget_id`: closes that specific window. Without arg (v0.1.1
+With `widget_id`: closes that specific window (DOES close persistent
-bw-compat): closes the focused (last-opened) window. Clears any open
+windows — explicit modder action). Without arg (v0.1.1 bw-compat):
+closes the focused (last-opened) window — **BUT** v0.3.0 makes this
+a no-op when the focused window is `persistent=true`. Clears any open
 context-menu when the last open window is closed.
 
 ---
 
+### `panel.point_in_any_panel(x, y)`
+
+**Syntax:** `panel.point_in_any_panel(x: number, y: number) -> bool`
+
+**Example:**
+```lua
+-- In a module's M.update(dt):
+local mx, my = engine.input.get_mouse_pos()
+if engine.input.was_mouse_pressed(engine.input.MOUSE_LEFT) then
+    if not panel.point_in_any_panel(mx, my) then
+        -- click landed on canvas — paint!
+        canvas.paint(mx, my)
+    end
+end
+```
+
+Returns `true` if screen-coord `(x, y)` falls within the bounds of ANY
+currently-open panel window (regardless of z_tier or input_block).
+Intended for module-side canvas-click logic — modules read input
+directly via `engine.input.*` and can use this helper to skip
+canvas-paint when the click landed on a panel widget area. Returns
+`false` if no panels are open.
+
+---
+
 ### `panel.toggle(widget_id)`
 
 **Syntax:** `panel.toggle(widget_id: string) -> void`
@@ -346,6 +398,73 @@ If you relied on the v0.1.1 "open(B) closes A" behavior, call
   window, or nil if not open.
 - `panel._test_get_screen_size()` — current screen size used by layouts.
 
+## v0.3.0 — Z-Tiers, Persistent, Input-Block
+
+### Z-Tiers
+
+Three rendering tiers, drawn bottom-to-top:
+
+| Tier | Render order | Default `input_block` | Use-case |
+|------|--------------|-----------------------|----------|
+| `"hud"` | first (background) | `"none"` | HP-bars, status displays, world-overlays |
+| `"normal"` | second | `"self"` | Toolbars, persistent panels, workbench windows |
+| `"top"` | third (foreground) | `"all"` | Modal dialogs, blocking confirmations |
+
+Within a tier, windows render in `open_order` (later-opened = drawn
+later = on top of same-tier earlier-opened). Hit-test iterates reverse
+z-tier (top → normal → hud); within tier reverse-open-order
+(last-opened first). Unknown tier names raise a loud-error at
+`panel.register` (typos surface immediately).
+
+### Persistent Windows
+
+```lua
+panel.register("toolbar", widget, {
+    z_tier      = "normal",
+    layout      = "top",
+    persistent  = true,        -- open at register-time
+    input_block = "self",
+})
+```
+
+`persistent=true` pushes the window onto `open_order` immediately and
+makes `panel.close()` (no arg) a **no-op** when the window is focused.
+Use this for in-game UI that must stay visible (toolbars, layer-pickers,
+palettes, HUDs). The modder can still close it explicitly with
+`panel.close(widget_id)`.
+
+ESC-equivalent paths (default-trigger keys, arg-less `panel.close()`)
+will NOT dismiss persistent panels. This protects users from
+accidentally hiding their toolbar.
+
+### Input-Block Routing (v0.3.0)
+
+`opts.input_block` controls whether mouse events are absorbed:
+
+| Value | Behavior |
+|-------|----------|
+| `"none"` | Window is never hit-tested. Mouse events pass through to lower windows. Use for HUD overlays. |
+| `"self"` | Hit-test the window's own bounds. Clicks inside → widget; clicks outside → fall through to next window. Default for normal tier. |
+| `"all"` | Modal. Hit-test self; clicks outside the window are swallowed (do not reach lower windows or the game-layer). Default for top tier. |
+
+If any open window has `input_block="all"`, ALL outside-misses are
+swallowed at the bottom of dispatch — this is the "modal block"
+semantic. Game-layer code (canvas-paint, world-click) should consult
+`panel.point_in_any_panel(x, y)` before reacting to clicks, since
+panel-lib does not intercept clicks the module reads via `engine.input.*`
+directly.
+
+Tier-defaults: hud→`"none"`, normal→`"self"`, top→`"all"`.
+
+### Test backdoors (v0.3.0 additions)
+
+- `panel._test_get_render_order()` — array of widget_ids in the order
+  `M.render()` would iterate (per-tier, within-tier open-order).
+- `panel._test_get_input_block(id)` — resolved input_block for a
+  registered window, or nil.
+- `panel._test_get_persistent(id)` — persistent flag for a registered
+  window, or nil.
+
 ## Theme Schema
 
 | Key | Default | Description |

init.lua

@@ -1,17 +1,22 @@
 -- =====================================================================
--- lib-core.panel v0.2.0 — Generic overlay-panel framework (Multi-Active)
+-- lib-core.panel v0.3.0 — Generic overlay-panel framework (Window-Manager)
 --
--- v0.2.0 evolves the v0.1 single-active model into a multi-active
+-- v0.3.0 layers z_tiers (hud → normal → top), persistent windows, and
--- window-manager with 11 named layout-slots + custom-fn hook. All
+-- input_block routing (none/self/all) on top of v0.2.0's multi-active +
--- v0.1.1 callers keep their semantics via a backward-compatibility
+-- layout-slot model. Render iterates per-z-tier (hud → normal → top);
--- shim (open/close/is_open without id-arg operate on the focused panel
+-- input dispatch iterates reverse (top → hud, within-tier reverse-open-
--- = last-opened).
+-- order). `persistent=true` registers a window as open-from-register-time
+-- and exempts it from bw-compat close() (modder must explicit-close).
 --
 -- Provides:
 --   - Widget registry + lifecycle (register, open, close, toggle)
---   - Multi-active open_order (last-opened = focused = topmost)
+--   - Multi-active open_order (last-opened = focused = topmost within tier)
 --   - 11 named layout-slot templates + opts.layout = function(sw, sh)
---   - Per-frame input dispatch with reverse-open-order hit-test
+--   - Z-tier rendering: hud (bottom) → normal → top (drawn last)
+--   - Persistent windows: open at register-time; ESC-equivalent no-op
+--   - Input-block routing: none / self / all (modal swallows misses)
+--   - panel.point_in_any_panel(x,y): public hit-test for module-side canvas
+--   - Per-frame input dispatch with reverse-z-tier reverse-open-order hit
 --   - Context-menu (show, hit-test, auto-close) on top of windows
 --   - Default-trigger binding via lib-core.input (lazy-required)
 --   - Optional pause-gate (any open widget with pause_on_open=true)
@@ -27,12 +32,11 @@
 --   - engine.render.measure_text(text, font_size) → w, h
 --
 -- Screen-size limitation: engine.render does NOT expose get_screen_size()
--- to Lua (GetScreenWidth/GetScreenHeight are C-only). v0.2 still falls
+-- to Lua (GetScreenWidth/GetScreenHeight are C-only). v0.3 still falls
 -- back to 1280x720 constants matching the default Sporel window config.
 --
--- DEFERRED (v0.2 non-goals):
+-- DEFERRED (v0.3 non-goals):
---   - Persistent panels (always-on HUD widgets) → v0.3
+--   - Focus API (focus / raise / lower) → v0.4
---   - z_tier other than "normal" (modal, hud, system) → v0.4
 --   - Drag + resize → v0.4
 --   - Keyboard navigation within widgets
 --   - Panel animation (fade in/out)
@@ -125,6 +129,28 @@ local function estimate_menu_width(actions, padding)
     return max_w
 end
 
+-- =====================================================================
+-- v0.3.0 — Z-Tiers + Input-Block defaults
+-- =====================================================================
+
+-- Z-Tier constants. Bottom-to-top render order = HUD (drawn first =
+-- background), then normal (toolbars/persistent panels), then top
+-- (drawn last = modal dialogs). Input dispatch iterates reverse.
+local VALID_Z_TIERS = { hud = true, normal = true, top = true }
+local Z_TIER_ORDER  = { "hud", "normal", "top" }
+
+-- Default input_block per tier when widget does not specify one.
+--   hud: pure cosmetic overlay, never absorbs input (HUD bars, status).
+--   normal: absorbs clicks within own bounds (persistent toolbars).
+--   top: modal; swallows clicks that miss it too (blocking dialogs).
+local DEFAULT_INPUT_BLOCK_BY_TIER = {
+    hud    = "none",
+    normal = "self",
+    top    = "all",
+}
+
+local VALID_INPUT_BLOCK = { none = true, self = true, all = true }
+
 -- =====================================================================
 -- v0.2.0 — Layout slots (per Phase Panel-WM spec §4.1)
 -- =====================================================================
@@ -235,6 +261,25 @@ local function render_one_window(widget_id, win, sw, sh)
     local panel_x, panel_y, panel_w, panel_h = bounds.x, bounds.y, bounds.w, bounds.h
     local padding = theme.padding
 
+    -- v0.3.0: chromeless widgets skip the panel-lib decorations (bg /
+    -- border / title bar / close-X) entirely. The widget gets the FULL
+    -- panel bounds as ctx.bounds (no title-bar inset). Intended for
+    -- in-game persistent HUD widgets (toolbars, layer-pickers, palettes)
+    -- that want to render their own chrome.
+    if win.opts.chromeless then
+        win._content_bounds = {
+            x = panel_x, y = panel_y, w = panel_w, h = panel_h,
+        }
+        win._close_button_rect = nil
+        local widget_ctx = {
+            bounds     = win._content_bounds,
+            theme      = M.get_theme(),
+            is_focused = (widget_id == open_order[#open_order]),
+        }
+        widget_def.render(widget_ctx)
+        return
+    end
+
     -- Background
     engine.render.draw_rect(panel_x, panel_y, panel_w, panel_h, theme.bg_color)
 
@@ -334,32 +379,48 @@ end
 
 --- _dispatch_event(event): route a synthetic or real input event.
 --- event = {kind="click", x, y, button="left"|"right"} or {kind="wheel", dy}
+---
+--- v0.3.0 routing:
+---   1. Context-menu (if open) always wins.
+---   2. Iterate reverse z_tier (top → normal → hud), within tier
+---      reverse-open-order. For each open window:
+---      - input_block="none": skip hit-test entirely (HUD passes through).
+---      - else: hit-test bounds; on hit route to widget.
+---   3. If no window claimed the event AND any open window has
+---      input_block="all": swallow (modal block).
+---   4. Else drop (no game-routing — module handles its own input).
 local function _dispatch_event(event)
     -- Context-menu always wins if open (consumes the next click).
     if ctx_menu then
         if dispatch_context_menu_event(event) then return end
     end
 
-    -- Iterate reverse-open-order (last-opened = topmost gets first crack).
     local sw, sh = get_screen_size()
+    local saw_modal = false  -- track if any input_block="all" window is open
+
+    -- Iterate reverse z-tier (top first), within tier reverse-open-order.
+    for ti = #Z_TIER_ORDER, 1, -1 do
+        local tier_name = Z_TIER_ORDER[ti]
         for i = #open_order, 1, -1 do
             local widget_id = open_order[i]
             local win = windows[widget_id]
-        if win and win.open then
+            if win and win.open and win.opts.z_tier == tier_name then
+                if win.opts.input_block == "all" then
+                    saw_modal = true
+                end
+                if win.opts.input_block ~= "none" then
                     local b = resolve_bounds(win.opts.layout, sw, sh)
-
-            -- Click events use hit-test against window bounds.
                     if event.kind == "click" then
                         if event.x and event.y
                         and event.x >= b.x and event.x < b.x + b.w
                         and event.y >= b.y and event.y < b.y + b.h then
-                    -- Close-button intercept (top-right X): left-click closes
+                            -- Close-button intercept (top-right X): left-click
-                    -- the window before forwarding to the widget.
+                            -- closes the window before forwarding to the widget.
                             if event.button == "left" then
                                 local cb = win._close_button_rect
                                 if not cb then
-                            -- Render hasn't run yet (e.g. test-mode); compute now
+                                    cb = close_button_rect(b.x, b.y, b.w,
-                            cb = close_button_rect(b.x, b.y, b.w, theme.padding, theme.font_size_title)
+                                        theme.padding, theme.font_size_title)
                                 end
                                 if event.x >= cb.x and event.x < cb.x + cb.w
                                 and event.y >= cb.y and event.y < cb.y + cb.h then
@@ -368,10 +429,11 @@ local function _dispatch_event(event)
                                 end
                             end
 
-                    -- Route click to widget
                             local content = win._content_bounds
                             if not content then
-                        -- Render hasn't run; compute content bounds now
+                                if win.opts.chromeless then
+                                    content = { x = b.x, y = b.y, w = b.w, h = b.h }
+                                else
                                     local padding = theme.padding
                                     local title_area_h = theme.font_size_title + padding * 2
                                     content = {
@@ -381,6 +443,7 @@ local function _dispatch_event(event)
                                         h = b.h - title_area_h - padding,
                                     }
                                 end
+                            end
                             local widget_ctx = {
                                 bounds     = content,
                                 theme      = M.get_theme(),
@@ -389,13 +452,16 @@ local function _dispatch_event(event)
                             win.widget_def.handle_input(widget_ctx, event)
                             return
                         end
-                -- v0.2.0: no input_block tiers yet — miss falls through to next window
-                -- (v0.3.0 will add modal-blocking)
                     elseif event.kind == "wheel" then
-                -- Wheel events route to the focused window (last-opened).
+                        -- Wheel routes to the focused (last-opened) window
+                        -- regardless of tier — once we reach the focused id
+                        -- in tier-walk order we forward and stop.
                         if widget_id == open_order[#open_order] then
                             local content = win._content_bounds
                             if not content then
+                                if win.opts.chromeless then
+                                    content = { x = b.x, y = b.y, w = b.w, h = b.h }
+                                else
                                     local padding = theme.padding
                                     local title_area_h = theme.font_size_title + padding * 2
                                     content = {
@@ -405,6 +471,7 @@ local function _dispatch_event(event)
                                         h = b.h - title_area_h - padding,
                                     }
                                 end
+                            end
                             local widget_ctx = {
                                 bounds     = content,
                                 theme      = M.get_theme(),
@@ -416,7 +483,15 @@ local function _dispatch_event(event)
                     end
                 end
             end
-    -- v0.2.0: events that hit no panel are dropped (no game-routing yet)
+        end
+    end
+
+    -- No window claimed the event. If any modal-block ("all") is open,
+    -- swallow the event so it does not reach the game-layer. Otherwise
+    -- drop it silently (modules read engine.input directly for canvas
+    -- interactions and can call panel.point_in_any_panel(x,y) to skip
+    -- clicks that fall within a panel area).
+    if saw_modal then return end
 end
 
 -- -----------------------------------------------------------------------
@@ -437,7 +512,12 @@ end
 ---   layout = "center" (default) | "left" | "right" | "top" | "bottom" |
 ---            "top-left" | "top-right" | "bottom-left" | "bottom-right" |
 ---            "left-half" | "right-half" | function(sw, sh) -> {x,y,w,h}
----   z_tier = "normal" (default; v0.2.0 only "normal" exposed)
+---   z_tier = "hud" | "normal" (default) | "top"
+---   persistent = bool (default false) — if true, window auto-opens at
+---                register-time and panel.close() without arg becomes a
+---                no-op when it's focused (modder must close(id) explicit).
+---   input_block = "none" | "self" | "all" — defaults per tier:
+---                   hud → "none", normal → "self", top → "all".
 function M.register(widget_id, widget_def, opts)
     if type(widget_id) ~= "string" then
         error("panel.register: widget_id must be a string, got " .. type(widget_id))
@@ -458,20 +538,49 @@ function M.register(widget_id, widget_def, opts)
         error("panel.register: duplicate widget_id '" .. widget_id .. "'")
     end
     opts = opts or {}
+
+    -- v0.3.0: validate z_tier + input_block eagerly so typos loud-error
+    -- at register-time (not at the next frame's render/dispatch).
+    if opts.z_tier ~= nil and not VALID_Z_TIERS[opts.z_tier] then
+        error(string.format(
+            "panel.register: unknown z_tier '%s' (must be hud|normal|top)",
+            tostring(opts.z_tier)), 2)
+    end
+    if opts.input_block ~= nil and not VALID_INPUT_BLOCK[opts.input_block] then
+        error(string.format(
+            "panel.register: unknown input_block '%s' (must be none|self|all)",
+            tostring(opts.input_block)), 2)
+    end
+
     -- Validate opts.layout eagerly (so unknown-slot errors surface at register, not later).
     local sw, sh = get_screen_size()
     local _validation_bounds = resolve_bounds(opts.layout, sw, sh)
     _ = _validation_bounds  -- discard; bounds re-resolved per-frame to react to screen-resize
 
+    local z_tier      = opts.z_tier or "normal"
+    local input_block = opts.input_block or DEFAULT_INPUT_BLOCK_BY_TIER[z_tier]
+    local persistent  = opts.persistent == true
+    local chromeless  = opts.chromeless == true
+
     widgets[widget_id] = widget_def
     windows[widget_id] = {
         widget_def = widget_def,
         opts = {
             layout      = opts.layout,                  -- nil OR string OR fn
-            z_tier = opts.z_tier or "normal",
+            z_tier      = z_tier,
+            persistent  = persistent,
+            input_block = input_block,
+            chromeless  = chromeless,
         },
         open = false,
     }
+
+    -- v0.3.0: persistent windows are open from register-time and pushed
+    -- onto open_order so they appear in render + hit-test immediately.
+    if persistent then
+        open_order[#open_order + 1] = widget_id
+        windows[widget_id].open = true
+    end
 end
 
 --- M.unregister(widget_id)
@@ -507,8 +616,11 @@ function M.open(widget_id)
 end
 
 --- M.close(widget_id?)
---- With id: closes that specific widget. Without id: closes the focused
+--- With id: closes that specific widget (DOES close persistent — explicit
---- (= last-opened) for v0.1.1 bw-compat.
+--- modder action). Without id: closes the focused (= last-opened) for
+--- v0.1.1 bw-compat — BUT v0.3.0 makes this a no-op when the focused
+--- window is persistent (ESC-equivalent should not dismiss persistent
+--- toolbars/HUDs).
 function M.close(widget_id)
     if widget_id == nil then
         -- bw-compat: close focused
@@ -518,9 +630,15 @@ function M.close(widget_id)
             return
         end
         widget_id = open_order[#open_order]
+        -- v0.3.0: persistent windows are exempt from arg-less close
+        -- (so ESC / `panel.close()` cannot dismiss persistent panels).
+        if windows[widget_id] and windows[widget_id].opts.persistent then
+            return
+        end
     end
     local w = windows[widget_id]
     if not w or not w.open then return end
+    -- Explicit close(id) DOES close persistent windows (modder-controlled).
     w.open = false
     local idx = find_in_array(open_order, widget_id)
     if idx then table.remove(open_order, idx) end
@@ -564,6 +682,29 @@ function M.is_pausing()
     return false
 end
 
+--- M.point_in_any_panel(x, y) → bool
+--- Returns true if screen-coord (x,y) falls within the bounds of ANY
+--- currently-open panel window (regardless of z_tier or input_block).
+--- Intended for module-side canvas-click logic: modules read input
+--- directly via engine.input.* but should skip canvas-paint when the
+--- click landed within a panel-widget area. Returns false if no panels
+--- are open.
+function M.point_in_any_panel(x, y)
+    if #open_order == 0 then return false end
+    local sw, sh = get_screen_size()
+    for _, id in ipairs(open_order) do
+        local w = windows[id]
+        if w and w.open then
+            local b = resolve_bounds(w.opts.layout, sw, sh)
+            if x >= b.x and x < b.x + b.w
+            and y >= b.y and y < b.y + b.h then
+                return true
+            end
+        end
+    end
+    return false
+end
+
 -- -----------------------------------------------------------------------
 -- Theme
 -- -----------------------------------------------------------------------
@@ -726,20 +867,24 @@ end
 -- -----------------------------------------------------------------------
 
 --- M.render()
---- Must be called each render frame. Iterates open_order bottom-up
+--- Must be called each render frame. v0.3.0: iterates per-z-tier
---- (last = focused = topmost) and draws each window. Renders any open
+--- (hud → normal → top) and within each tier walks open_order bottom-up
---- context-menu on top of all windows. No-op if nothing is open.
+--- so HUD draws first (= background) and modal top tier draws last (=
+--- topmost). Renders any open context-menu on top of all windows. No-op
+--- if nothing is open.
 function M.render()
     if #open_order == 0 then return end
     local sw, sh = get_screen_size()
+    for _, tier_name in ipairs(Z_TIER_ORDER) do
         for _, widget_id in ipairs(open_order) do
             local w = windows[widget_id]
-        if w and w.open then
+            if w and w.open and w.opts.z_tier == tier_name then
                 render_one_window(widget_id, w, sw, sh)
             end
         end
+    end
 
-    -- Context-menu (rendered on top of all windows)
+    -- Context-menu (rendered on top of all windows + tiers)
     if ctx_menu then
         render_context_menu()
     end
@@ -794,4 +939,36 @@ function M._test_get_screen_size()
     return get_screen_size()
 end
 
+--- M._test_get_render_order() — returns array of widget_ids in the
+--- order M.render() would iterate them (per-tier hud→normal→top, within
+--- tier in open_order). v0.3.0 addition.
+function M._test_get_render_order()
+    local out = {}
+    for _, tier_name in ipairs(Z_TIER_ORDER) do
+        for _, widget_id in ipairs(open_order) do
+            local w = windows[widget_id]
+            if w and w.open and w.opts.z_tier == tier_name then
+                out[#out + 1] = widget_id
+            end
+        end
+    end
+    return out
+end
+
+--- M._test_get_input_block(widget_id) — returns the resolved
+--- input_block string for an open window, or nil. v0.3.0 addition.
+function M._test_get_input_block(widget_id)
+    local w = windows[widget_id]
+    if not w then return nil end
+    return w.opts.input_block
+end
+
+--- M._test_get_persistent(widget_id) — returns the persistent flag for
+--- a registered window, or nil if not registered. v0.3.0 addition.
+function M._test_get_persistent(widget_id)
+    local w = windows[widget_id]
+    if not w then return nil end
+    return w.opts.persistent
+end
+
 return M

manifest.lib

@@ -1 +1 @@
-{"id":"lib-core.panel","version":"0.2.0","api_min":"0.1","deps":[]}
+{"id":"lib-core.panel","version":"0.3.0","api_min":"0.1","deps":[]}