Fix stale post-widen deck-reflow figures (90/144/1190px) across docs and tests, and split test_deck_groups.cpp's width-budget fixtures into a new file.

docs/PLAN.md

@@ -613,7 +613,9 @@ folded into the tracks below:
 - **Γ-F4** — there **is** an explicit loop enable, and it lives on the **chrome row**, not
   in a deck. W2-T2's scope grows accordingly — spec §6.4.
 - **Γ-F5** — MASTER's reserved slot is **one** cell. The 90 px headroom argument behind
-  that is spec §1.6 and governs every future control addition.
+  that is spec §1.6 and governs every future control addition. (**Moved afterwards:**
+  Γ-W3-T1 widened the row block, so §1.6's ledger is now 82 px — the ruling and its
+  purchasing power are unchanged, only the number.)
 - **Γ-F6** — **ship dynamic latency as ruled.** The `restartComponent(kLatencyChanged)`
   deactivate/reactivate the SDK mandates is accepted: *"the limiter will either be on or off
   on its instance, toggling during playback is not a use case."* No constant-latency
@@ -1083,9 +1085,9 @@ waveform band.
   Row 1's natural width fits the block **only after this track's `Band|Notch` move**: 1030
   today, +42 from W2-T1's PITCH/RATE, −92 here, = **980**. That is this track's fit assertion
   and W1-T4 deliberately left it open.
-- **The 90 px of remaining headroom is the budget for the life of this layout**, and one deck
+- **The 82 px of remaining headroom is the budget for the life of this layout**, and one deck
   cell is 60 px. **This is why MASTER's reserved slot is ONE cell** (Γ-F5, ruled): two would
-  spend 60 of the 90 up front on a control nobody has named, leaving 30 — which would freeze
+  spend 60 of the 82 up front on a control nobody has named, leaving 22 — which would freeze
   row 1 forever, since any later row-1 addition needs 60. Widening MASTER later costs the same
   60 it would cost now, and by then the trade is against a real control instead of a guess.
   **State this ledger where a future reader will hit it** — spec §1.6 is its home, and a

docs/TODO.md

@@ -365,7 +365,7 @@ The within-deck stacking idea is retired, not deferred.
 **The measured-geometry block that used to live here has been deleted, not moved.** It was
 taken at the 840 px floor with `kDeckCellW = 48` and is wrong twice over — Θ-W6-T1 changed
 both the floor (980) and the cell metrics (60 × 74). The current, re-derived geometry — every
-group's width, both row totals, and the resulting 1190 × 680 floor — is the table in
+group's width, both row totals, and the resulting 1198 × 680 floor — is the table in
 `docs/product/instrument-control-surface.md` §1.2. **Do not resurrect the old numbers.**
 The unresolved 864-vs-872 px VELOCITY↔VOICE adjacency-threshold discrepancy is retired with
 them; it was measured against a layout that no longer exists.

docs/product/instrument-control-surface.md

@@ -311,7 +311,7 @@ Two corollaries for a reader who wants to add something:
   FILTER's `Band|Notch` move exploits). A cell always costs its 60 px.
 - **The chrome row is a separate budget.** The toolbar row's right-anchored control run is
   paid for out of the *title* slot, not out of the window floor — which is why the loop
-  enable (§6.5) costs zero of the 90. That is a genuinely different purse and must not be
+  enable (§6.5) costs zero of the 82. That is a genuinely different purse and must not be
   confused with this one.
 
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