docs(product): settle Phase L §L7 forks F1/F2/F3 (capture-time stamp, interchangeable substrate, drag rule + cursor cues + Alt-replace)

CONTEXT.md

@@ -1692,10 +1692,10 @@ id→slot map) is settled at build; the *contract* below holds either way.
   trimmed for content-height purposes (the recommendation: trim trailing empties for scroll
   extent, keep interior gaps).
 - **Reorder:** the user drags a card to a target slot within its bank; the pure reorder mutator
-  moves that sample's position to the target slot, gap-preserving. (Whether a drop onto an
+  moves that sample's position to the target slot, gap-preserving. **Drop-into-empty-slot places
-  occupied slot displaces/swaps vs. inserts-and-shifts is settled at build — recommendation:
+  there; drop-onto-occupied inserts-before and shifts the tail** (matching common file-manager
-  **drop-into-empty-slot places there; drop-onto-occupied inserts before and shifts the tail**,
+  reorder) — SETTLED as the *default* drop. (The **Alt+drop-onto-occupied = REPLACE** override is
-  matching common file-manager reorder.)
+  specified below under Drag disambiguation, F3.)
 
 **JSON round-trip + migration (load-bearing).** `serialize`/`deserialize` stay lossless
 including positions (`deserialize(serialize(x)) == x`). **A pre-L7 project blob has no position
@@ -1708,13 +1708,20 @@ round-trip + legacy migration.
 **Undo.** A reorder is **one Ctrl-Z** — the actions/shell layer wraps the mutation in a batched
 undo point (`Undo_BeginBlock2`/`EndBlock2`), matching every existing bank-verb's undo discipline.
 
-**M9 overlap (flagged — Daniel's awareness).** M9 "slots" (capture-to-slot-N / insert-slot-N,
+**Position-model shape (F2 — SETTLED 2026-07-27: interchangeable substrate, NOT fixed slots).**
-MIDI-bindable, MPC-style) is **explicitly deferred (Daniel, 2026-07-26).** L7's sparse-slot
+The carrier is the **plain gap-preserving interchangeable-slot substrate** — a per-bank id→slot
-model is a **partial overlap:** it builds the *addressable-position substrate* M9 would sit on,
+map (Daniel: *"I don't think I want fixed slots MPC style, but the substrate of interchangeable
-but L7 adds **no** slot-numbered capture/insert actions and **no** MIDI bindings. Building L7
+slots is valuable"*). It is **not** M9-shaped: no slot *identities*, no numbered/addressable
-un-defers the *coordinate model* portion of M9, not the *action* portion. If Daniel wants the
+slots that persist independent of their occupant, no slot actions, no MIDI-bindable slot numbers,
-substrate to be explicitly M9-shaped (fixed numbered slots vs. a plain gap-preserving ordinal),
+no capture-to-slot-N. A slot is just a display position a sample occupies; dragging cards
-that is a fork to settle before the model is built.
+rearranges which sample sits where.
+
+**M9 overlap (awareness note — unchanged intent).** M9 "slots" (capture-to-slot-N /
+insert-slot-N, MIDI-bindable, MPC-style) remains **explicitly deferred (Daniel, 2026-07-26).**
+The interchangeable substrate L7 builds still *eases* a future M9 revival — it lays the
+addressable-position groundwork M9 would sit on — but L7 adds **no** slot-numbered capture/insert
+actions and **no** MIDI bindings. The "plain vs. M9-shaped" sub-fork is closed: plain
+gap-preserving substrate, per F2 above.
 
 ### 2. Decorative metadata overlay (bars.beats · s.ms)
 
@@ -1728,17 +1735,17 @@ subtle shadowed variant for legibility over the peaks), subordinate to the wavef
 the speed constraint (no animation).** Pure formatting helpers (below) are unit-tested; only the
 kit draw is shell.
 
-**Bars.beats source (FORK F1 — Daniel to confirm).** bars.beats.subdivisions requires a
+**Bars.beats source (F1 — SETTLED 2026-07-27: capture-time stamp).** bars.beats.subdivisions
-**tempo + time-signature** reference. `Sample` already carries `captureTempo` (BPM at capture)
+requires a **tempo + time-signature** reference. `Sample` already carries `captureTempo` (BPM at
-and `lengthBeats`, but **no time-signature.** Two options:
+capture) and `lengthBeats`, but **no time-signature.** **Decision: capture-time stamp** — add
-- **(recommended) Capture-time stamp:** add `captureTimeSigNum` / `captureTimeSigDenom` to
+`captureTimeSigNum` / `captureTimeSigDenom` to `Sample` + its JSON round-trip, stamped on the
-  `Sample` + its JSON round-trip, stamped on the capture path (read the project meter at capture
+capture path (read the project meter at capture via the REAPER meter API — verify
-  via the REAPER meter API — verify `TimeMap_GetTimeSigAtTime` / equivalent against the SDK at
+`TimeMap_GetTimeSigAtTime` / equivalent against the SDK at build). bars.beats.subdivisions renders
-  build). *Why recommended:* the label is **stable** as the project's tempo/meter later changes;
+from the stamped tempo + meter, **stable under later project tempo/meter changes** — a bank sample
-  a bank sample outlives the project state it was captured under, matching the existing
+outlives the project state it was captured under, matching the existing `captureTempo` stamp
-  `captureTempo` stamp philosophy. **Cost:** this is a **capture-path write beyond draw work** —
+philosophy. This is a **capture-path write beyond draw work** (its own checkbox in the PLAN, now
-  its own flagged checkbox; old samples with no stamp fall back gracefully (blank musical
+settled). Old samples with no stamp fall back gracefully (blank musical read-out, or a documented
-  read-out, or a documented assumed 4/4).
+assumed 4/4).
 - **(rejected) Live project meter at draw time:** the label would drift under the card as the
   project tempo/meter changes, and would be wrong for any sample captured under a different
   meter than the project's current one.
@@ -1766,30 +1773,81 @@ grid-card interaction states stay **visually distinct and coherent:**
   `accent/hot` outline on the target slot) must not be confusable with the purple selection
   border; spec the exact treatment at build.
 
-### Drag disambiguation (FORK F3 — proposed rule, Daniel to confirm)
+### Drag disambiguation (F3 — SETTLED 2026-07-27)
 
 In-grid reorder must coexist with the existing internal bank-move/copy drag and OS drag-out.
-**Proposed precedence (one clean rule, evaluated live during the drag):**
+**Precedence (one clean rule, evaluated live during the drag):**
 1. **Pointer leaves the client rect → OS drag-out** (unchanged; `drag_out::decideGesture` wins
    first — the existing invariant #4 boundary).
 2. **Else drop lands on a tab / the OTHER region's bank → move/copy** (unchanged; Ctrl = copy).
 3. **Else drop lands within the SAME bank's own grid → reorder-to-slot** (new).
+   - Onto an **empty** slot → place there.
+   - Onto an **occupied** slot, **no modifier** → insert-before-and-shift-tail (the default,
+     above).
+   - Onto an **occupied** slot, **Alt held** → **REPLACE** the occupant (below).
 
 So: leave-client wins → else other-bank wins → else same-bank-grid = reorder. The precedence is
 encoded in a **pure decision helper** (mirror `drag_out::decideGesture`); the shell reads the
-live pointer + focused region + client rect and calls it. This keeps the reorder gesture from
+live pointer + focused region + client rect + **modifier state (Alt)** and calls it. This keeps
-ever stealing an intended bank-move or OS-drag, and keeps a same-bank in-grid drag from being
+the reorder gesture from ever stealing an intended bank-move or OS-drag, and keeps a same-bank
-mis-read as a no-op (today a same-bank drop is a no-op; L7 gives it reorder meaning).
+in-grid drag from being mis-read as a no-op (today a same-bank drop is a no-op; L7 gives it
+reorder meaning).
+
+**Alt+drop-onto-occupied = REPLACE (SETTLED 2026-07-27).** Holding **Alt** at drop over an
+occupied slot **replaces the occupant** instead of inserting-and-shifting. Replace semantics,
+precisely:
+- The replaced sample is **removed from THAT bank's index only** — same semantics as the existing
+  remove-from-bank verb (`BankBook::removeSample` index-only). **The file stays on disk;** the
+  owned-manifest and Phase R prune govern its bytes. If the replaced sample's last reference
+  disappears, that is exactly the existing cross-bank-reference story (`hashReferencedElsewhere`
+  reports whether the hash is still referenced elsewhere; prune later reclaims a now-orphaned
+  owned file). Replace introduces **no new deletion authority** — it never touches the disk.
+- The dragged sample then takes the vacated slot (the slot's position is preserved; only its
+  occupant changes).
+- **Pool case (un-evacuable pool — SETTLED rule).** The pool's privileges (un-deletable,
+  un-renamable, **un-evacuable**, never zero banks) are enforced in `bank_book`. **Alt+Replace is
+  allowed in the pool only when it does not violate a pool privilege.** Concretely: replacing a
+  pool entry is an index-only removal of that pool sample; it is **permitted** as long as it does
+  not empty the pool below the pool's floor and does not remove the *last* reference in a way the
+  pool's rules forbid. The consistent rule the model enforces: **the replace's index-removal step
+  is the same operation as remove-from-bank, and it must pass the same pool-privilege guard that
+  remove already applies — if remove-from-pool would be rejected for that sample, Alt+Replace over
+  it is rejected too** (the drop falls back to a no-op or the default insert-shift; settle the
+  exact rejection UX at build). No special pool-only replace path; one rule, guarded by the
+  existing pool invariants.
+
+**Drop-result cursor cues (SETTLED 2026-07-27 — REAPER-idiomatic special cursors).** During a
+drag the cursor must indicate **what the drop will do**, following REAPER's idiomatic use of
+distinct action cursors. The cue set:
+- **Reorder-to-slot** (within the same bank's grid) — a move/reorder cursor.
+- **Move/copy to another bank or tab** — the move (or copy, when Ctrl is held) cursor, matching
+  the existing internal-drag semantics.
+- **OS drag-out** (pointer left the client rect) — the OS copy/drag cursor (owned by the OS drag
+  loop once handed off).
+- **Replace** — a distinct replace cursor, shown **only when Alt is actually held over an
+  occupied slot** (i.e. only when precedence resolves to the Alt+replace case). It must not appear
+  over an empty slot or when Alt is not held.
+
+**Shell mechanism:** the shell sets the cursor via Win32/SWELL `SetCursor` (REAPER ships its own
+action-cursor idiom as the visual reference — match its feel; load or synthesize kit-consistent
+cursors at build). **The *decision* of which cue applies stays in the pure gesture/disambiguation
+helper** — the same helper that resolves precedence returns the resolved gesture (reorder / move /
+copy / os-drag-out / replace), and the shell maps that pure result to a cursor. No cue logic in
+the shell; the shell only owns the `SetCursor` call and the cursor resources.
 
 ### Pure/shell discipline (L7)
 
-Model: the position carrier + gap semantics + reorder mutator + JSON round-trip/migration are
+Model: the position carrier + gap semantics + **reorder mutator + Alt-replace mutator** (the
-**pure** (in `bank_book`, CTest-covered to the bar of its existing round-trip). Layout: the
+latter reusing the existing index-only remove-from-bank semantics + pool-privilege guard) + JSON
-sparse-aware slot↔rect math + point→slot hit-test + the drag-disambiguation decision are **pure**
+round-trip/migration are **pure** (in `bank_book`, CTest-covered to the bar of its existing
-(extend `bank_grid`; mirror `mode_switch` / `drag_out::decideGesture`). Formatting: the
+round-trip). Layout: the sparse-aware slot↔rect math + point→slot hit-test + the
-bars.beats and s.ms formatters are **pure**. Shell (DAW-bound): the reorder drag wiring +
+drag-disambiguation decision (**including the resolved-gesture result that drives the cursor cue,
-drop-target highlight, the capture-time-signature stamp (F1) read on the capture path, and the
+and the Alt-over-occupied → replace resolution**) are **pure** (extend `bank_grid`; mirror
-kit overlay/selection-border draw. The L1 kit draws; no palette/font decision re-opened.
+`mode_switch` / `drag_out::decideGesture`). Formatting: the bars.beats and s.ms formatters are
+**pure**. Shell (DAW-bound): the reorder/replace drag wiring + drop-target highlight, the
+**cursor `SetCursor` call mapping the pure resolved-gesture to a cursor resource**, the
+capture-time-signature stamp (F1, settled) read on the capture path, and the kit
+overlay/selection-border draw. The L1 kit draws; no palette/font decision re-opened.
 
 ## The L3 gate + Phase S coordination contract
 

PLAN.md

@@ -389,50 +389,55 @@ is model + layout + draw only; the "capture ≠ placement" principle is untouche
 > per-sample ordinal/slot to the persisted state and its JSON round-trip + a migration for
 > existing projects — scoped honestly below, model work separated from draw work.
 
-> **Forks for Daniel (surface before build — see CONTEXT.md §L7):**
+> **Forks — all SETTLED 2026-07-27 (see CONTEXT.md §L7 for full detail):**
-> - **F1 — bars.beats source.** `Sample` already carries `captureTempo` (BPM at capture) and
+> - **F1 — SETTLED: capture-time stamp.** Add `captureTimeSigNum` / `captureTimeSigDenom` to
->   `lengthBeats`, but **no time-signature field.** bars.beats.subdivisions needs a
+>   `Sample`, stamped on the capture path alongside the existing `captureTempo`;
->   time-signature reference. **Recommendation: a capture-time stamp** (add `captureTimeSigNum`
+>   bars.beats.subdivisions renders from the stamped tempo + meter, stable under later project
->   /`captureTimeSigDenom` to `Sample`, stamped on the capture path) so the label is stable as
+>   changes. Live-meter-at-draw-time rejected (would drift). The capture-path stamp checkbox
->   the project tempo/meter later changes — matching the existing `captureTempo` stamp
+>   below is **settled, not flagged.**
->   philosophy. This adds a **capture-path stamp beyond draw work** (its own checkbox below,
+> - **F2 — SETTLED: plain interchangeable-slot substrate, NOT fixed MPC-style slots.** The
->   flagged). Alternative (live project meter at draw time) is rejected: the label would drift
+>   carrier is a **per-bank id→slot map** (gap-preserving interchangeable slots): a slot is just a
->   under the card as the project changes, and a bank sample outlives the project state it was
+>   display position an occupant sits in — **no slot identities, no numbered/addressable slots, no
->   captured under.
+>   slot actions, no MIDI-bindable slot numbers, no capture-to-slot-N.** The "plain vs. M9-shaped"
-> - **F2 — M9 un-deferral awareness.** M9 "slots" (capture-to-slot-N / insert-slot-N,
+>   sub-fork is closed (plain). M9 (capture-to-slot-N / insert-slot-N, MIDI-bindable, MPC-style)
->   MIDI-bindable, MPC-style) is **explicitly deferred (Daniel, 2026-07-26).** L7's sparse
+>   stays **explicitly deferred (Daniel, 2026-07-26);** the substrate still eases a future M9
->   placement is a **partial overlap** — both need addressable grid positions. Building L7's
+>   revival but L7 adds no M9 actions or bindings.
->   sparse-slot model effectively lays the *position substrate* M9 would sit on, but L7 does
+> - **F3 — SETTLED + EXTENDED.** Drag precedence: leave-client → OS drag-out; else tab/other-bank
->   **not** add slot-numbered capture/insert actions or MIDI bindings. Flagged so Daniel knows
+>   → move/copy (Ctrl = copy); else same-bank grid → reorder-to-slot. **Extensions:**
->   L7 un-defers the *coordinate model* portion of M9, not the *action* portion. If Daniel wants
+>   (a) **drop-result cursor cues** — the cursor indicates the drop result via REAPER-idiomatic
->   the slot substrate to be explicitly M9-shaped (numbered addressable slots vs. a plain
+>   special cursors (reorder / move / copy / OS-drag-out / replace); the shell sets it via
->   gap-preserving ordinal), that is a fork to settle before the model checkbox.
+>   Win32/SWELL `SetCursor`, but the *decision* of which cue applies stays in the pure gesture
-> - **F3 — drag-disambiguation rule (proposed, Daniel to confirm).** The panel already has
+>   helper. (b) **Alt+drop-onto-occupied = REPLACE** — default occupied-slot drop stays
->   internal bank-move/copy drag and OS drag-out. In-grid reorder must coexist. **Proposed
+>   insert-and-shift; holding Alt replaces the occupant (index-only removal, existing
->   rule:** a drag whose drop lands **within the SAME bank's own grid** = **reorder-to-slot**;
+>   remove-from-bank semantics — file stays on disk, prune governs bytes, `hashReferencedElsewhere`
->   a drop on **a tab / the other region's bank** = **move/copy** (as today); a drag that
+>   handles last-reference). **Pool rule:** Alt+Replace in the un-evacuable pool is allowed only
->   **leaves the client rect** = **OS drag-out** (as today). One clean precedence: leave-client
+>   when the same pool-privilege guard that `remove` applies would permit removing that sample —
->   wins → else other-bank wins → else same-bank-grid = reorder. See CONTEXT.md §L7.
+>   one rule, no pool-only path; the replace cursor cue shows only when Alt is actually held over
+>   an occupied slot.
 
 **Verify (in DAW):** capture several samples; drag a card to a new position within its bank —
 the order persists across project save/reload and Ctrl-Z restores the prior order; drag the
 first card below the second so the first row is empty — the gap holds across reload; each card
 shows bars.beats.subdivisions bottom-left and s.ms bottom-right, legible over the peaks; a
 selected card shows the normal cell with a purple (`accent/tertiary`) border — no inversion —
-and hover / focus / drag-target remain distinct; dragging a card to another bank's tab still
+and hover / focus / drag-target remain distinct; during any drag the cursor shows the correct
-moves/copies (not reorder), and dragging out of the panel still starts an OS file drag; an
+special cue (reorder within the bank, move/copy over a tab/other bank, OS drag-out past the client
-existing project (saved before L7) loads cleanly with cards in their prior insertion order.
+edge); Alt+drop over an occupied card **replaces** the occupant (the replaced sample leaves that
+bank's grid but its file survives on disk; if it was the last reference, prune later reclaims it),
+and the replace cursor appears only while Alt is held over an occupied slot; dragging a card to
+another bank's tab still moves/copies (not reorder), and dragging out of the panel still starts an
+OS file drag; an existing project (saved before L7) loads cleanly with cards in their prior
+insertion order.
 **Depends on:** L1 (the kit) for all draw; sequences **after L6** (both rework the same
 `bank_panel` grid). **Ungated by Phase S** (the dock panel is on dev); independent of the L3
 gate. No `capture` / `insert` behavior change; no palette/font decision re-opened.
 
 **(a) Persisted order + sparse-position model (pure, hard-tested) — model work, separate from draw:**
-- [ ] Add an explicit per-sample **display position** to the persisted bank state (gap-preserving
+- [ ] Add an explicit per-sample **display position** to the persisted bank state — a
-  ordinal or slot coordinate — settle the shape against F2). Decide the home: `bank_model`
+  **per-`Bank` id→slot map in `bank_book`** (gap-preserving interchangeable slots, per F2
-  is stated untouched by `bank_book`'s wrapping — position is a **per-bank display concern**, so
+  settled). `bank_model` / `Sample` stay untouched (position is a per-bank display concern, not a
-  it belongs with the bank's membership, not on `Sample`. Candidate: a per-`Bank` ordered/keyed
+  `Sample` property — a copy of a sample into two banks may sit at different slots). **No slot
-  position map in `bank_book` (id → slot), leaving `bank_model` / `Sample` untouched. Settle the
+  identities / numbered addressable slots** — a slot is just a position an occupant sits in.
-  exact carrier at build.
 - [ ] JSON round-trip for the position data (`serialize`/`deserialize` remain lossless:
   `deserialize(serialize(x)) == x` including positions).
 - [ ] **Migration for existing projects** (old blobs with no position data): load cleanly with a
@@ -440,32 +445,54 @@ gate. No `capture` / `insert` behavior change; no palette/font decision re-opene
   a pre-L7 project is visually identical on first load post-L7.
 - [ ] **Gap semantics on insert / delete / prune** (pure, tested): a new capture takes the next
   free slot after the last occupied one (append); a delete/remove/prune **leaves a gap** (does
-  not re-pack) so positions stay stable; define whether an empty trailing tail is trimmed.
+  not re-pack) so positions stay stable. **Confirmed defaults:** trailing empty tail trimmed for
+  scroll-extent purposes; interior gaps preserved.
 - [ ] **Reorder mutator** (pure): move sample `id` to target slot within its bank, gap-preserving;
-  deterministic; unit-tested.
+  deterministic; unit-tested. Drop-into-empty places there; **drop-onto-occupied (default, no
-- [ ] Undo integration: a reorder is one Ctrl-Z (batched undo point in the actions/shell layer,
+  modifier) inserts-before-and-shifts-tail.**
-  matching the existing bank-verb undo discipline).
+- [ ] **Alt-replace mutator** (pure): Alt+drop over an occupied slot **replaces the occupant** —
+  index-only removal of the occupant from THAT bank (reuse the existing remove-from-bank
+  semantics: file stays on disk, owned-manifest/prune govern bytes, `hashReferencedElsewhere`
+  handles the last-reference case), then the dragged sample takes the vacated slot (position
+  preserved). **Pool guard:** if the sample sits in the un-evacuable pool, the replace's
+  index-removal step passes the **same pool-privilege guard that `remove` applies** — if
+  remove-from-pool would be rejected for that sample, Alt+Replace over it is rejected (falls back
+  to no-op / default insert-shift; settle rejection UX at build). One rule, no pool-only path.
+  Deterministic; unit-tested. **No new deletion authority — never touches disk.**
+- [ ] Undo integration: a reorder **or a replace** is one Ctrl-Z (batched undo point in the
+  actions/shell layer, matching the existing bank-verb undo discipline).
 
 **(b) Reorder-drag gesture + slot hit-test (pure geometry + shell wiring):**
 - [ ] **Sparse-aware grid layout** (pure, extend `bank_grid`): map per-slot positions (with gaps)
   to `CellRect`s — an empty slot is drawn empty (or skipped), not back-filled. Slot ↔ pixel-rect
   math + point→slot hit-test stay pure and unit-tested (mirror `mode_switch`/`bank_grid`).
-- [ ] **Drag-disambiguation** (F3): drop within the same bank's grid = reorder-to-slot; drop on a
+- [ ] **Drag-disambiguation** (F3): drop within the same bank's grid = reorder-to-slot (empty =
-  tab / other bank = move/copy (unchanged); leave client = OS drag-out (unchanged). Precedence
+  place; occupied+no-modifier = insert-shift; **occupied+Alt = replace**); drop on a tab / other
+  bank = move/copy (unchanged, Ctrl = copy); leave client = OS drag-out (unchanged). Precedence
   encoded in a **pure decision helper** (mirror `drag_out::decideGesture`); shell reads live
-  pointer + region + client rect and calls it.
+  pointer + region + client rect + **modifier state (Alt)** and calls it. The helper returns the
+  **resolved gesture** (reorder / move / copy / os-drag-out / replace) so the shell can map it to
+  a cursor cue.
+- [ ] **Drop-result cursor cues** (F3 extension): the shell sets a REAPER-idiomatic special cursor
+  per the pure resolved-gesture (reorder / move / copy / OS-drag-out / replace) via Win32/SWELL
+  `SetCursor`; the **replace** cursor shows only when Alt is actually held over an occupied slot.
+  **Cue-decision logic stays in the pure helper;** the shell owns only the `SetCursor` call and
+  the cursor resources (load/synthesize kit-consistent cursors at build; REAPER's own action
+  cursors as the visual reference).
 - [ ] Shell wiring: on a same-bank reorder drop, resolve the target slot via the pure hit-test and
-  call the reorder mutator; drop-target slot highlight during the drag (distinct from the existing
+  call the reorder mutator (or, when Alt is held over an occupied slot, the **Alt-replace
-  region/tab drop highlights).
+  mutator**); drop-target slot highlight during the drag (distinct from the existing region/tab
+  drop highlights, and — for a pending replace — distinct from the pending-reorder highlight).
 
 **(c) Metadata overlay (pure formatting + kit draw):**
 - [ ] **Pure formatters, unit-tested:** `bars.beats.subdivisions` from `lengthSeconds` +
   `captureTempo` + capture-time signature (F1) and `seconds.milliseconds` from `lengthSeconds`.
   Deterministic string output; edge cases (zero length, missing tempo → graceful blank/fallback).
-- [ ] **[FLAGGED — F1, capture-path stamp beyond draw work] Capture-time signature stamp:** add
+- [ ] **Capture-time signature stamp (F1, settled — capture-path write beyond draw work):** add
   `captureTimeSigNum` / `captureTimeSigDenom` to `Sample` + its JSON round-trip, stamped on the
-  capture path (read the project meter at capture). Only needed if F1 resolves to the capture-time
+  capture path (read the project meter at capture — verify `TimeMap_GetTimeSigAtTime` / equivalent
-  stamp (recommended). Old samples with no stamp fall back gracefully in the formatter.
+  against the SDK at build). Old samples with no stamp fall back gracefully in the formatter
+  (blank musical read-out, or a documented assumed 4/4).
 - [ ] **Kit draw:** overlay the two strings on the card — bars.beats bottom-LEFT, s.ms
   bottom-RIGHT — via the kit `text()` in the micro / value-mono class, `text/dim` (or a subtle
   shadowed variant for legibility over the waveform); **decorative, non-interactive** (no
@@ -513,15 +540,16 @@ Phase S to reach dev. Phase S feature work runs in parallel, ungated by Phase L.
   pure module; sourced from the registered action phrase, prefix stripped at draw time); item-move
   and track-tag action ids confirmed; active-mode read confirmed via the same
   `view().activeModeId()` the footer toggle uses.
-- **L7 model + tempo surface (L7)** — settle at L7 build/spec-review: (1) **position carrier** —
+- **L7 model + tempo surface (L7)** — forks F1/F2/F3 **all settled 2026-07-27** (see the §L7
-  where the per-sample display position lives (candidate: a per-`Bank` id→slot map in `bank_book`,
+  forks block above and CONTEXT.md §L7): position carrier = per-`Bank` id→slot map in `bank_book`
-  keeping `bank_model`/`Sample` untouched per CLAUDE.md); (2) **F1 bars.beats source** — confirm
+  (plain interchangeable substrate, `bank_model`/`Sample` untouched); F1 = capture-time signature
-  the capture-time signature stamp with Daniel (recommended) vs. live project meter; the stamp adds
+  stamp; F3 = drag precedence + REAPER-idiomatic cursor cues + Alt-replace-over-occupied with the
-  a capture-path write (its own flagged checkbox); (3) **F2 M9 overlap** — confirm L7's sparse-slot
+  stated pool guard. **Remaining build-time verification (SDK/API, not product decisions):**
-  substrate is not mis-scoped as M9's slot *actions*; (4) **F3 drag rule** — confirm the
+  (1) the REAPER meter-read API for the F1 stamp (`TimeMap_GetTimeSigAtTime` or equivalent) —
-  same-bank-grid = reorder / other-bank = move-copy / leave-client = OS-drag precedence. Verify the
+  verify signature/argument order against the SDK; (2) the Win32/SWELL `SetCursor` path and cursor
-  REAPER meter-read API for the stamp (`TimeMap_GetTimeSigAtTime` or equivalent) against the SDK at
+  resource loading/synthesis for the drop-result cues — confirm the cursor idiom against SWELL and
-  build.
+  REAPER's own action cursors; (3) confirm the existing remove-from-bank pool-privilege guard is
+  reusable as-is for the Alt-replace index-removal step.
 
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