docs: record Phase Gamma Wave 2's two landed tracks in COMPLETED

docs/COMPLETED.md

@@ -1049,3 +1049,87 @@ excess 18.52 %, pitch-synchronous excess 0.00 %** — PSOLA eliminates that corn
 than regressing it, with every splice at n = 1 landing exactly one source period away.
 **These figures are a one-machine, Debug-build measurement against the named control arm,
 not a general performance claim.**
+
+### Γ-W2-T1 — pitch-rate-deck
+
+PITCH became PITCH/RATE: three knobs (`Key Trk | Rate | Pitch`) under the existing
+Varisp|Presrv toggle, both new controls wired through the engine. Rate is 50–200 % on a
+taper linear in semitones over ±12 (the stated exception to the centre-expansion law),
+note-on latched; Pitch is a ±24 st baseline offset, live. Keytrack × rate × pitch-offset
+compound into a single read-increment multiply — the per-sample path gained nothing.
+Merged as `9dbb8b8`. Spent the phase's second payload rung, v16, as a strict suffix; a
+v15 blob lifts to rate 100 % / pitch 0 st.
+
+**`isLiveDeckParam` was renamed `deckParamCommit`** and now returns a three-state
+`LiveCommit` (`Live` / `NoteOnLatched` / `Reload`) rather than a bool — one predicate
+widened, not a second mechanism. **Γ-W4-T1 derives the VST3 exposed parameter set from
+this predicate**, so the classification is load-bearing two waves out.
+
+**The clamp question the plan left open at `[propose at review]` was resolved as one
+clamp:** `clampStretchRate` at the stretcher, with the taper taking its bounds as
+parameters and `deck_values` aliasing them from `engine::kStretchRateMin`/`Max`.
+
+**Code review found one Critical, fixed before merge:** the resample bake derived its
+frame window without the two new fields while rendering *with* them, so a bake at any
+non-unity Rate — or, under Varispeed, a downward Pitch — wrote a truncated file into the
+bank. Fixed by deriving the window from the rate the voice actually reads at; the
+regression test judges against a measured reference render rather than a recomputed
+formula, and was proved non-vacuous by reverting the fix (every non-unity case fails).
+
+**A ruling folded in during remediation:** Pitch was an uncompensated stage-time coupling
+under Varispeed — a Trigger AHD's wall-clock attack was invariant under Rate but scaled
+with Pitch. Pitch is now compensated; key-track and velocity remain deliberately
+uncompensated, because those are shipped sounds whose compensation would break
+bit-identity at non-root notes.
+
+**A Varispeed golden hash was added**, honestly labelled: unlike the Preserve constants
+(witnessed against pre-track commit `0a7778b`), it was captured from the remediation
+commit itself, so it stands as a witness for the *next* track rather than proof of this
+one.
+
+### Γ-W2-T2 — loop-crossfade-ux
+
+An explicit loop enable, a legible mark grammar, and the crossfade painted where it is
+heard. **No format change** — no `ComponentState` version moved, no new persisted field,
+`resolveLoop` untouched, audio unchanged. The enable **is** `SampleLoop::hasLoop`, whose
+provenance changes from marker-gesture-derived to user-owned, with the gestures as
+shortcuts onto it. Merged as `a8e30a9`. A new pure module,
+`core/instrument/ui/loop_marks`, holds the state machine (`resolveLoopMarks`/
+`applyLoopMarks`); the four marks (START/LOOP/END/XFADE) get one grammar — line + shaped
+cap + label, the cap being the grip — with cap/label/suppression geometry pure and
+unit-tested.
+
+**The crossfade moved to `[loopEnd − crossfade, loopEnd)`** and draws as a
+top-and-bottom edge wedge, never a second fill; the loop fill's peak alpha stays exactly
+0.20.
+
+**START draws in `overlay/trace`, NOT `accent/primary` as the spec table states** —
+because `accent/primary` *is* the waveform fill, so a primary START would measure 1:1
+against the material it marks. `overlay/trace` measures 3.071:1 against the fill and
+3.065:1 against `bg/base`, clearing the 3:1 non-text floor on both. **This is a
+deliberate deviation from `docs/product/instrument-control-surface.md` §6.3's table**,
+and the spec is what is wrong.
+
+**Code review found three Majors, all fixed before merge:** a parked-vs-off state leak
+where dragging START on a fresh capture silently converted "never set" into "LOOP OFF";
+three text draws landing on the lime waveform fill at 1.58:1 and 1.10:1 (fixed with a
+`bg/base` scrim at alpha 0.90, solved for the binding case rather than chosen by eye — it
+lands at 4.666:1 / 8.091:1 and is pinned in `test_theme.cpp`); and a per-mouse-move
+bridge read plus bank parse in the hover path, now memoized against the existing key
+struct.
+
+**`docs/TODO.md`'s "Pre-existing staged-envelope-node shadow at zero-attack" entry was
+resolved incidentally** — giving START a cap is what closed it — and rewritten in place
+with the recorded outcome by the track itself.
+
+**One thing is deliberately NOT settled and is recorded here as open, not as accepted:**
+the audible wedge draws `accent/secondary` against the `overlay/trace` envelope trace at
+**1.60:1** against a 3:1 floor. The 0.20 fill-alpha constraint is met and the
+pre-existing accepted 2.25:1 pair is unmoved, but the under-floor *extent* inside the
+loop span grows from two 2 px marker columns to two `crossfadeWidth × 10 px` bands. No
+alpha fixes it — the pair is intrinsic to teal-on-violet. **Daniel has this: he is
+judging it visually in the DAW and has not yet ruled.**
+
+**Neither track has been verified in a running DAW; both are asserted in CTest only.**
+The full test suite passes on the merged result — **99/99, Debug config, on one
+machine** — not a general cross-platform or Release-config claim.