diff --git a/CLAUDE.md b/CLAUDE.md
index c9e6460..568db5a 100644
--- a/CLAUDE.md
+++ b/CLAUDE.md
@@ -131,6 +131,12 @@ There is no hot-reload. Copy the built binary into REAPER's `UserPlugins/` folde
   3. `rec->Register("hookcommand", ...)` — receives every action fired; claim only your own id, return `false` otherwise.
   4. On unload (`rec == nullptr`), mirror-unregister everything with the same strings prefixed by `'-'`.
 
+## Product design docs
+
+`docs/product/` holds the product-design reasoning behind each phase — the "why we chose this" that predates the spec. They are large and are cited by section from `CONTEXT.md` and `PLAN.md`; **grep for the cited section rather than reading a file whole**. `docs/cmake-cheatsheet.md` is a standalone build-system reference.
+
+Files: `capture-tail.md`, `code-organization.md`, `design-view.md`, `midi-playback.md`, `multi-bank.md`, `provenance.md`, `removal-and-prune.md`, `versioning-and-release.md`, `visual-design-language.md`.
+
 ## The load-bearing principle
 
 **Capture and placement are separate acts.** Capturing audio writes a file to the bank and adds an index entry. It **never** puts an item in the arrange view. Placement is a distinct, on-demand action (`insert` module / `InsertMedia`). Any code path that auto-inserts a capture into the timeline violates the purpose of the tool and **must be rejected in review**.
diff --git a/COMPLETED.md b/COMPLETED.md
index b263fa5..d68b938 100644
--- a/COMPLETED.md
+++ b/COMPLETED.md
@@ -248,7 +248,7 @@ membership count visible, offlined-FX caveat surfaced as a tooltip.
 - [x] Segmented mode switch `[ Arrange | Design ]` in the window header; active lit.
 - [x] Wire the switch to the toggle/activate actions from D4.
 - [x] Per-mode membership count display.
-- [x] Offlined-FX re-init caveat as a tooltip on the switch.
+- [ ] Offlined-FX re-init caveat as a tooltip on the switch. (Not built — no trace in source; did not survive the Phase L panel redesign.)
 
 **Notes/decisions:**
 - New PURE module `src/mode_switch.{h,cpp}` — REAPER-free layout math for the
@@ -298,8 +298,9 @@ mass-tag on the first poll after open).
 **Depends on:** D2-W1.
 
 - [x] Apply managed-lane ops in the view shell (`I_FREEMODE`/`I_FIXEDLANE`/
-  `C_LANEPLAYS`/`B_FIXEDLANE_HIDDEN` via the item/track info setters;
-  `UpdateTimeline()` after `I_FREEMODE`); **managed lanes only, never manual**.
+  `C_LANEPLAYS` via the item/track info setters; `UpdateTimeline()` after `I_FREEMODE`);
+  **managed lanes only, never manual**. `B_FIXEDLANE_HIDDEN` is read-only per the SDK and
+  is not written — lane visibility follows from `C_LANEPLAYS`.
   Verify every flag name/signature against the SDK header.
 - [x] New-content detection on the bank_panel timer: diff the live track/item GUID
   set against the previous poll; tag any GUID new since the last poll to the
@@ -1450,7 +1451,7 @@ never auto-insert (the buttons only fire the existing, unchanged actions).
 - **Maintenance cluster restored to top toolbar** (Daniel's directive during L4 build): the
   initial L4 spec described the top toolbar as "capture + placement" only; the landed
   implementation includes re-capture and cancel-realtime in a Maintenance cluster on the same
-  top toolbar. CONTEXT.md and CLAUDE.md updated to reflect the actual layout.
+  top toolbar. CLAUDE.md updated to reflect the actual layout.
 - New pure module `src/footer_bar.{h,cpp}`: footer layout/hit-test (narrow mode toggle +
   Tail button + Prune); no LICE or REAPER types. New CTest target `footer_bar_tests`.
 - `action_bar` gained `ActionCluster::Tagging` and `ActionCluster::Switching` for the
@@ -1913,7 +1914,7 @@ default. The keyboard-strip drag machinery is still built here, but in service o
 capture-first layout. All layout/hit-test math is **pure geometry** (new `keyboard_strip` +
 a `capture_browser` layout module — mirrors of `mode_switch`/`editor_geometry`); the LICE
 draw + drag-state machine is the editor shell. RT discipline untouched (edits commit
-off-thread via `commitMapAndReload`); the instrument stays a **read-only bank consumer**.
+off-thread via `commitAndReload`); the instrument stays a **read-only bank consumer**.
 CONTEXT-ARCHIVE.md §Phase S (ReaSampler 9000 UX — capture-first editor).
 
 **Policy reversal — fresh instance is SILENT, nothing auto-selected (was S4).** The S4
@@ -1975,7 +1976,7 @@ source of drawing). The drag machine's `WM_MOUSEMOVE` tracking also lights the k
   boundary rounding). Mirror of `mode_switch`/`editor_geometry`.
 - [ ] Editor shell drag-state machine: `WM_LBUTTONDOWN` grabs a card / a key / a zone
   edge-or-body, `WM_MOUSEMOVE` updates the in-flight edit against the pure resolver,
-  `WM_LBUTTONUP` commits via the existing `commitMapAndReload` (off-thread reload; RT path
+  `WM_LBUTTONUP` commits via the existing `commitAndReload` (off-thread reload; RT path
   untouched). Live visual feedback while dragging; a single undo-coherent edit on release.
 
 ### S10-Z — Zones panel (opt-in multi-zone keymap editing; demoted from the default face)
@@ -2000,7 +2001,7 @@ the next held note); zone add/select/delete work; the ±1 nudge row is gone.
   residual).
 - [ ] Zone edit via the shared strip: draw the keyboard strip + zone bars in LICE, drive
   the shared drag-state machine (edge = resize, body = move, key = root), commit via
-  `commitMapAndReload`. Zone add/select/delete as single affordances; ±1 nudge row gone.
+  `commitAndReload`. Zone add/select/delete as single affordances; ±1 nudge row gone.
 
 ---
 
@@ -2043,7 +2044,7 @@ zero-crossing snap is a small pure helper over the decoded PCM.
   house style; draw the loop markers over it. Reuses the S10 drag-state machine.
 - [ ] Loop-point edit → performance-map override: a dragged loop writes a per-zone loop
   override (seeded from the S2 bank intrinsic, D-B), committed off-thread via
-  `commitMapAndReload`; the bank intrinsic is never written back (instrument is a read-only
+  `commitAndReload`; the bank intrinsic is never written back (instrument is a read-only
   bank consumer). Extends `PerformanceZone` with an optional loop override (additive, same
   shape as `rootOverride`) + its component-state (de)serialize (version bump, back-compat
   with S5's v2 map blob — a truncated/older blob defaults the override absent).
@@ -2174,9 +2175,9 @@ Gate/ADSR behavior is unchanged when hold=0 (regression).
 `PerformanceZone` the mode + params attach to), S11 (Gate loop-point UI; Trigger's waveform
 shows start + %-length + fades on the same waveform surface). Independent of S7.
 
-- [x] Core: `PlayMode { Gate, Trigger }` on the voice + the envelope split. **Gate** grows
-  `AdsrParams` → `AhdsrParams` (add `holdFrames` between attack and decay; hold=0 is the
-  exact current ADSR — back-compat). **Trigger** is a distinct envelope: play `[start,
+- [x] Core: `PlayMode { Gate, Trigger }` on the voice + the envelope split. **Gate**: `AdsrParams`
+  gains `holdFrames` in place (AHDSR hold stage between attack and decay; `holdFrames == 0` is
+  the exact pre-S15 ADSR — back-compat; no type rename). **Trigger** is a distinct envelope: play `[start,
   start + lengthFraction·(frames−start))` with a **fade-in** ramp (0→1 over `fadeInFrames`)
   and a **fade-out** ramp (1→0 over `fadeOutFrames` ending at the play-length end),
   **ignoring note-off** (release is a no-op in Trigger). Fade curve default **equal-power**
@@ -2199,7 +2200,7 @@ shows start + %-length + fades on the same waveform surface). Independent of S7.
   markers** (S11's loop UI); **Trigger** shows **start + %-length end + fade-in/out**
   handles on the same waveform. A **mode toggle** per capture/zone in the guided setup
   (S10) / Zones panel (S10-Z). Marker/handle geometry is pure; commits off-thread via
-  `commitMapAndReload`. The instrument stays a **read-only bank consumer**. **Editor control
+  `commitAndReload`. The instrument stays a **read-only bank consumer**. **Editor control
   surface deferred to S12 tier (spec-sanctioned).**
 
 ---
@@ -2324,9 +2325,11 @@ save/reopen rebinds by the correct UID; nothing plays differently (identity/pair
 **Depends on:** V4 (`app_version` channel-identity single-source), S1 (VST3 factory identity).
 
 - [x] **Beta VST3 class UID (the permanent commitment).** Second FOREVER-STABLE class UID
-  (`REASAMPLER_PROC_UID_BETA_1..4` + `kReaSamplerProcessorUIDBeta`) alongside the existing
-  stable UID in `reasampler_vst.h`. The channel bit selects which UID the factory registers
-  (`DEF_CLASS2`) — compile-time, one class per binary. Both UIDs frozen forever.
+  (`REASAMPLER_PROC_UID_BETA_1..4`) alongside the existing stable UID in `reasampler_vst.h`.
+  A `#if REASAMPLER_CHANNEL_IS_BETA` block selects `REASAMPLER_ACTIVE_UID_*`, which feeds the
+  single `kReaSamplerProcessorUID` — no separate beta-named constant. The channel bit selects
+  which UID the factory registers (`DEF_CLASS2`) — compile-time, one class per binary. Both UIDs
+  frozen forever.
 - [x] **Channel-derived binary + display identity (no scattered `#ifdef`s).** Binary name:
   CMake VST3 target `OUTPUT_NAME` forks by channel — `reasampler_9000` (stable) /
   `reasampler_9000_beta` (beta) — via `REASAMPLER_VST_OUTPUT_NAME`. Display name: factory
diff --git a/CONTEXT-ARCHIVE.md b/CONTEXT-ARCHIVE.md
index 61490e3..a2f4207 100644
--- a/CONTEXT-ARCHIVE.md
+++ b/CONTEXT-ARCHIVE.md
@@ -564,7 +564,7 @@ where RS5K is one-shot, and bank-integrated ingest where RS5K is file-at-a-time.
 change — D-A settled); **all layout/hit-test math in pure geometry modules** (mirror of
 `mode_switch` / `editor_geometry` / `embed_strip`), the draw + drag-state machine in the
 shell; RT discipline untouched (every edit commits **off** the audio thread via the
-existing `commitMapAndReload` → off-thread `reloadFromBank` → atomic swap); the instrument
+existing `commitAndReload` → off-thread `reloadFromBank` → atomic swap); the instrument
 stays a **read-only bank consumer** (loop/root/ADSR edits are the instrument's *performance
 map*, D-B — never written back to the bank); component-state persistence and
 read-only-over-bank stay settled.
diff --git a/CONTEXT.md b/CONTEXT.md
index 74048c3..e2667d1 100644
--- a/CONTEXT.md
+++ b/CONTEXT.md
@@ -1027,7 +1027,7 @@ S10's single-capture setup surface shape.
 markers**; Trigger shows **start + %-length end + fade-in/out** handles — same waveform, same
 pure `frame↔pixel` + marker-grab geometry module (S11), mode switches which markers draw. A
 **mode toggle** per capture/zone sits in the S10 guided setup / S10-Z Zones panel. Every edit
-commits **off-thread** via `commitMapAndReload`; the instrument stays a **read-only bank
+commits **off-thread** via `commitAndReload`; the instrument stays a **read-only bank
 consumer** (mode/params are performance map, never written to `Sample` or the bank).
 
 ### Pitch engine modes — Varispeed vs Preserve (S16)
@@ -1876,7 +1876,7 @@ face without scrolling, and cannot be resized below the constraint floor.
   compat surface in S-VIEW and is the substance of fork R10-F1. `keyTrack` and `previewVelocity`
   remain fully bit-identical on lift. No existing field changes.
 - **RT discipline (unchanged).** The preview-trigger fires a note through the existing voice engine
-  via the off-audio-thread commit path (`commitMapAndReload` idiom); no new `process`-thread work,
+  via the off-audio-thread commit path (`commitAndReload` idiom); no new `process`-thread work,
   no allocation on the audio thread.
 - **VST3 class UID unchanged.** A view reorganization + additive param is **not** a compat event;
   saved instances rebind and restore. The UID stays the S-NAME-1/S18 forever-locked identity.
@@ -1919,7 +1919,7 @@ preview velocity **persists** via envelope-v6 `ComponentState`; the envelope ove
 - **Drop-to-FX** — `TrackFX_AddByName` / `TrackFX_SetNamedConfigParm` / `GetThingFromPoint` all
   **verified present** in `reaper_plugin_functions.h`; the remaining work is **runtime diagnosis**
   (name match, gesture routing, blob format), not an SDK question.
-- **Preview note through the voice engine off-thread** — confirm the existing `commitMapAndReload`
+- **Preview note through the voice engine off-thread** — confirm the existing `commitAndReload`
   / off-thread reload idiom is the right seam to fire a one-shot preview note without touching
   `process` on the UI thread; no torn state on the atomic voice-engine pointer.
 - **Preview-velocity persistence seam (S-VIEW-F1)** — the envelope-v6 `ComponentState` field is the