fix #425: pack resident budget is a 1080p ceiling that scales with pixel count; an explicit Apply retries a failed selection

Live Holtburg at 2560x1440: the Low preset needed 67,368,164 resident bytes
(screen-sized HDR/depth/ray targets are 44 MB of that) against an absolute
64 MiB ceiling that had only been validated at 1080p, so Options -> Apply
fell back to the default path; every later Apply was then refused by the
controller's failure memo, which treated the user's deliberate choice like
automatic re-activation.

RenderPackResidentBudget.Effective scales the declared 1080p figure by the
viewport's pixel-count ratio (never below 1), still capped by the hardware
MaxPackResidentBytes; both pack graphs use it and the performance-matrix
tool judges its resident column by the same rule (contract test updated).
RenderPackController.Request gains explicitUserChoice, which clears the
memo for that selection; RenderPackSelectionBinding passes it on every
display edge (Apply, including resolution changes) and keeps the memo for
the startup request.

Tests: RenderPackResidentBudgetTests (1080p/720p keep the declared
ceiling, 1440p = 16/9x, 4K = 4x, hardware cap wins, zero extent rejected);
controller explicit-retry; the binding test now proves the user's next
Apply activates once the cause is gone. App hermetic lane 6,068/0 (Release).

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

docs/ISSUES.md

@@ -24,6 +24,44 @@ What does NOT go here:
 - Every session: scan OPEN issues at start; promote/close anything we touched during the session before ending.
 - Promoting to a Phase: mark as `DONE (promoted to Phase X)` + commit SHA where the Phase entry landed.
 
+## #425 — Options Apply "Atmospheric rendering" fell back to the default path and stayed locked out: Low's 64 MiB resident budget did not scale with resolution
+
+**Status:** ✅ FIXED 2026-08-23 (found at the owner's VM3/VM6 gate launch).
+**Component:** rendering / render packs (Campaign AR budget contract + activation memo)
+
+**Symptom:** live Holtburg, 2560×1440 fullscreen; Options → Atmospheric rendering →
+Apply → the panel snapped back to "acdream default". Log
+(`artifacts/owner-gate/launch2.log`): first Apply `Render pack preset 'low'
+needs 67368164 resident GPU bytes after materializing its scene-dependent
+shadow command buffers; the active pack budget is 67108864 bytes`, then every
+later Apply `This pack selection already failed for the current registration
+and will not be retried.`
+
+**Two root causes:** (1) a preset's `MaxResidentGpuBytes` (Low 64 / Medium 128 /
+High 256 MiB) was applied as an absolute ceiling at any resolution, but the
+pack's resident set is dominated by screen-sized images (12 B/px HDR+depth plus
+ray/bloom intermediates): Low's targets are 25 MB at 1080p and 44 MB at 1440p,
+and live Holtburg's shadow command buffers took the total to 64.25 MiB — 0.4 %
+over. Medium would have failed the same way at 4K. The ceilings were only ever
+validated at 1080p. (2) The controller's failure memo keyed the user's explicit
+Apply and automatic re-activation identically, so one failed attempt locked
+that selection out until restart even after the cause (resolution, scene)
+changed.
+
+**Fix:** `RenderPackResidentBudget.Effective` — the declared figure is the 1080p
+ceiling, scaled by the viewport's pixel-count ratio (never below 1) and still
+capped by the hardware's `MaxPackResidentBytes`; used by both pack graphs and
+mirrored in `tools/run-atmospheric-performance-matrix.ps1` so the tool judges
+1440p/4K rows by the same rule. `RenderPackController.Request(selection,
+explicitUserChoice: true)` clears the memo for that selection; the settings
+binding passes it for every display edge (the user's Apply, including a
+resolution change); startup keeps the memo. Tests:
+`RenderPackResidentBudgetTests`, `An_explicit_user_request_retries_a_selection_that_failed_earlier`,
+the extended `Selection_binding_activates_only_at_boundary_and_persists_failed_fallback`,
+and the matrix contract test. Not a workaround: the ceiling now means what the
+budget table implied ("at 1080p"), and a deliberate user action is allowed to
+try again.
+
 ## #424 — Client crashed on alt-tab out of exclusive fullscreen: zero-area frame reached `RenderPackActivationExtent.Validate`
 
 **Status:** ✅ FIXED 2026-08-23 (same session it was found — the owner's VM6/VM3 gate launch).

docs/plans/2026-08-21-atmospheric-rendering.md

@@ -739,7 +739,7 @@ CPU-submission-bound. Fullscreen work may occupy currently idle GPU time, but
 it is not treated as free. Shadow cascades must protect the CPU submission
 path.
 
-| Preset | Incremental GPU p50 / p99 at 1080p | Incremental render-CPU p50 / p99 | Pack-owned resident GPU memory |
+| Preset | Incremental GPU p50 / p99 at 1080p | Incremental render-CPU p50 / p99 | Pack-owned resident GPU memory **at 1080p** (scales with pixel count — `RenderPackResidentBudget.Effective`, #425) |
 |---|---:|---:|---:|
 | Low | ≤ 2.0 / 3.0 ms | ≤ 0.15 / 0.50 ms | ≤ 64 MiB |
 | Medium | ≤ 3.25 / 4.50 ms | ≤ 0.25 / 0.75 ms | ≤ 128 MiB |