feat(launcher): route all UI strings through t(key) indirection

strings.lua holds English defaults. ctx.t(key, ...) looks up the key,
optionally string.formats with extra args, and falls back to '[key]'
for missing entries. All panels and init.lua sweep clean of inline
literals — verified by a grep over '"[A-Z][a-z][a-z ]+"'. This sets
up v2's localization-lib-pattern (separate slice, ADR-0036 trigger)
to swap STRINGS without touching the launcher code.

strings.lua

@@ -0,0 +1,20 @@
+return {
+    -- Empty-state hint
+    empty_hint            = "Select a module to see details.",
+    -- Detail panel sections
+    dependencies          = "Dependencies",
+    -- Launch flow
+    launch_module         = "Launch Module",
+    cancel                = "Cancel",
+    launch_anyway         = "Launch anyway",
+    -- Conflict modal
+    conflict_title        = "Dependency conflict",
+    conflict_body_line1   = "This module has unresolved dependencies.",
+    conflict_body_line2_fmt = "Missing libs: %d",
+    -- Quit modal (already in v0.2.0 but moves to strings now)
+    quit_prompt           = "Quit Sporel?",
+    yes                   = "Yes",
+    no                    = "No",
+    -- News entry default title
+    news_default_title    = "News",
+}