test: sugar-form + mixed-form assertions for parse_lua_surface (S2 follow-up)

8 new assertions (sugar-form: 5, mixed-form: 3). Total 35 -> 43.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

README.md

@@ -8,13 +8,13 @@ Per Fault-Injection-Audit-Convention (2026-05-16):
 
 | Function | Assertion-Count | Coverage |
 |---|---|---|
-| `parse_lua_surface` | 7 | Happy-path (2 public + 1 private), empty-source edge |
+| `parse_lua_surface` | 15 | Happy-path (2 public + 1 private), empty-source edge, sugar-form (`function M.foo`), mixed-form (sugar + explicit) |
 | `parse_readme_api` | 4 | Standard H3-pattern, no-API-section edge |
 | `diff_surface` | 5 | Equal (no diff), surface-superset (missing), doc-superset (stale) |
 | `grep_engine_calls` | 5 | 3 unique calls, no-calls edge |
 | `generate_topology_block` | 6 | Lib-with-deps+engine, asset-lib (no deps, no engine) |
 | `validate_readme_structure` | 8 | Complete core, missing-API core, missing-Topology, missing-Badges, community-tier-no-enforcement |
-| **TOTAL** | **35** | |
+| **TOTAL** | **43** | |
 
 ### Tested-Surface
 - All 6 public functions of `lib-core.api-discovery` v0.1.0.

init.lua

@@ -27,6 +27,37 @@ return M
         local empty = api.parse_lua_surface("local M = {}\nreturn M")
         engine.test.equals(#empty.public, 0, "parse_lua_surface: empty source = no public")
         engine.test.equals(#empty.private, 0, "parse_lua_surface: empty source = no private")
+
+        -- Sugar-form: function M.foo(...) end
+        local sugar_src = [[
+local M = {}
+function M.alpha(x) return x end
+function M.beta() end
+function M._sugar_private() end
+function not_in_M() end
+return M
+]]
+        local sugar_surface = api.parse_lua_surface(sugar_src)
+        engine.test.equals(#sugar_surface.public, 2,  "parse_lua_surface: sugar-form 2 public")
+        engine.test.equals(sugar_surface.public[1], "alpha", "parse_lua_surface: sugar-form first = alpha")
+        engine.test.equals(sugar_surface.public[2], "beta",  "parse_lua_surface: sugar-form second = beta")
+        engine.test.equals(#sugar_surface.private, 1, "parse_lua_surface: sugar-form 1 private")
+        engine.test.equals(sugar_surface.private[1], "_sugar_private", "parse_lua_surface: sugar-form private = _sugar_private")
+
+        -- Mixed form (sugar + explicit in same source)
+        local mixed_src = [[
+local M = {}
+function M.gamma() end
+M.delta = function() end
+return M
+]]
+        local mixed_surface = api.parse_lua_surface(mixed_src)
+        engine.test.equals(#mixed_surface.public, 2,  "parse_lua_surface: mixed-form 2 public")
+        -- Order: sugar-form parsed before explicit (per impl order)? Either is acceptable; use set-check:
+        local mixed_set = {}
+        for _, n in ipairs(mixed_surface.public) do mixed_set[n] = true end
+        engine.test.assert(mixed_set["gamma"], "parse_lua_surface: mixed-form gamma present")
+        engine.test.assert(mixed_set["delta"], "parse_lua_surface: mixed-form delta present")
     end
 
     -- ===== parse_readme_api =====