Ψ-W1-T3 review remediation: soften the double-fire claim to unspecified-by-SDK, mark the unload mirror [verify — DAW], fix stale comment, drop redundant assertions, dedupe hook-partitioning comments, drop what-comment; file the action_registry test-seam deferral.

docs/PLAN.md

@@ -2412,7 +2412,10 @@ must not touch `main.cpp`; this track is why.
   (`custom_action` / `hookcommand2` / `-custom_action` mirror) — a deliverable of this
   track.
 - **DAW-verification obligation:** Daniel adds the action to the Media Explorer toolbar
-  and imports from it; also confirms the Main-section binding still fires.
+  and imports from it; also confirms the Main-section binding still fires. Also: unload,
+  reload, confirm no duplicate Media Explorer entry — the `-custom_action` unload mirror
+  is unconfirmed against the SDK header (root `CLAUDE.md` §"REAPER extension contract",
+  `[verify — DAW]`), and if unsupported the entry leaks across a reload.
 
 **Open questions.** `[verify]` re-verify `custom_action_register_t` and `hookcommand2`
 argument order/types against the SDK headers at implementation time (root `CLAUDE.md`

docs/TODO.md

@@ -445,3 +445,40 @@ today.
 bitmap and confirmed to place the stroke correctly, or it is redesigned to rasterize at
 physical rather than logical resolution once `IPlugViewContentScaleSupport` (or
 equivalent) makes scaling real.
+
+## `ingestHandleSectionCommand` has no unit test
+
+**Context (what shipped — Ψ-W1-T3, media-explorer-section).** The Media-Explorer
+import now dispatches through two hooks — `ingestHandleCommand` (Main,
+`"hookcommand"`) and `ingestHandleSectionCommand` (Media Explorer,
+`"hookcommand2"`). Both live in `ingest.cpp`, which compiles straight into the
+`reaper_reasampler` MODULE target.
+
+**The wart.** No `shell/` translation unit in this repo has a test target — every
+`<module>_tests` executable is a `core/` pure-module target. `ingestHandleSectionCommand`
+is a two-line command-id comparison; correctness here rests on code review, not CTest.
+Review verified this constraint is real and the deferral correct.
+
+**Intended fix.** Make `action_registry` a linkable library and give it the repo's
+first `shell/` test target, driven by a fake `reaper_plugin_info_t`. Its own header
+(`reaper_plugin.h:153-172`) shows `Register` is a plain member-function pointer on the
+struct, not a REAPER API pointer resolved through `REAPERAPI_LoadAPI` — a fake instance
+needs no live REAPER process to exercise `rec->Register(...)` calls. Once
+`action_registry` is test-covered, move the Media-Explorer section registration into it.
+
+**The constraint the fix MUST handle.** The extraction alone buys nothing:
+`action_registry` has no test target today either, so lifting `ingestHandleSectionCommand`
+into it without also standing up the test target just relocates the untested code. The
+same follow-up could collapse `ingest.cpp:466-472`'s hand-rolled `command_id`+`gaccel`
+pair onto `action_registry::registerAction`, which already does exactly that dance for
+the Q-W6 table.
+
+**Priority / risk.** Low / deferred. `ingestHandleSectionCommand` is a two-branch
+comparison, reviewed and correct at this scope; the gap is the missing test seam, not a
+known defect.
+
+**Done looks like.** `action_registry` is a linkable library with its own `shell/`-first
+CTest target driven by a fake `reaper_plugin_info_t`; the Media-Explorer section
+registration and `ingestHandleSectionCommand` move into it and gain unit coverage; and
+`ingest.cpp`'s own `command_id`+`gaccel` registration collapses onto
+`action_registry::registerAction` where the shapes match.