refactor(app): compose atomic frame roots

Move the complete update/render construction graph into a typed Phase-8 owner, explicitly carry the content dependencies it consumes, and publish both roots through one exact lease. Extract lifecycle resource sampling and frame-owned late bindings so partial startup and shutdown withdraw the same generation without window callbacks.

Co-authored-by: Codex <codex@openai.com>

docs/plans/2026-04-11-roadmap.md

@@ -104,11 +104,11 @@ controllers, selection/radar, landblock publishers, and portal/sky/particle
 resources have transactional phase ownership and exact-owner late bindings.
 I.7 adds the complete streaming/session/hydration/local-player/teleport phase,
 including explicit reversible ownership for every late edge. `GameWindow` is
-now 2,149 raw lines after I.8a, which composes the session factory, command
-targets, and sole gameplay input subscriber before frame publication. I.8b–I.9,
+now 1,919 raw lines after I.8b, which also composes and atomically publishes the
+complete update/render pair and extracts lifecycle resource sampling. I.8c–I.9,
 shutdown, canonical soak snapshots, and closeout checkpoints J–L remain. The
-App gate passes 3,424 tests / 3 intentional skips, the complete Release suite
-passes 7,796 tests / 5 skips, and the I.8a corrected-diff review is clean.
+App gate passes 3,429 tests / 3 intentional skips, the complete Release suite
+passes 7,801 tests / 5 skips, and the I.8b corrected-diff review is clean.
 
 This is a behavior-preserving structural program. Severe regressions still get
 root-cause fixes in separate commits; ordinary feature work resumes with M4

docs/plans/2026-05-12-milestones.md

@@ -60,11 +60,13 @@ publishers, and portal/sky/particle resources have transactional phase
 ownership and exact-owner late bindings. I.7 now owns the complete streaming,
 session, hydration, local-player, combat, and teleport startup graph, including
 named reversible late edges. I.8a adds the focused live-session runtime factory
-and attaches command/input owners before frame publication. `GameWindow` is
-2,149 raw lines. I.8b–I.9 and checkpoints J–L remain active. Issue #232 tracks
+and attaches command/input owners before frame publication. I.8b composes and
+atomically publishes the complete frame pair and extracts lifecycle resource
+sampling. `GameWindow` is 1,919 raw lines. I.8c–I.9 and checkpoints J–L remain
+active. Issue #232 tracks
 process-residency variance in the soak without loosening its leak threshold.
-The App gate passes 3,424 tests / 3 skips, the complete Release suite passes
-7,796 tests / 5 skips, and the I.8a corrected-diff review is clean.
+The App gate passes 3,429 tests / 3 skips, the complete Release suite passes
+7,801 tests / 5 skips, and the I.8b corrected-diff review is clean.
 
 Carried:
 #153 far-teleport residual, #116 slide-response, the remaining R6 ownership cleanup plus

docs/plans/2026-07-22-gamewindow-slice-8-checkpoint-i-ordered-composition.md

@@ -294,9 +294,11 @@ ledger only after the complete pipeline is live.
   detailed session-binding, atomic-root, and terminal-start plan is
   [`2026-07-22-gamewindow-slice-8-checkpoint-i8-frame-roots-session-start.md`](2026-07-22-gamewindow-slice-8-checkpoint-i8-frame-roots-session-start.md).
   I.8a is complete: the session factory, command targets, and sole gameplay
-  input subscriber now belong to Phase 7 and publish before any frame root;
-  `GameWindow.cs` is 2,149 raw lines. I.8b atomic frame-root composition is the
-  active cut.
+  input subscriber now belong to Phase 7 and publish before any frame root.
+  I.8b composes the unchanged update/render graph in a focused phase, publishes
+  the pair through an exact owned slot lease, and moves lifecycle resource
+  sampling out of the window. `GameWindow.cs` is 1,919 raw lines. I.8c terminal
+  session start is the active cut.
   Checkpoint I remains active until I.9 closes the complete nine-phase pipeline.
 
 ## 6. Automated acceptance

docs/plans/2026-07-22-gamewindow-slice-8-checkpoint-i8-frame-roots-session-start.md

@@ -1,6 +1,6 @@
 # GameWindow Slice 8 — Checkpoint I.8 Frame Roots and Session Start
 
-**Status:** Active — I.8a complete; I.8b frame-root composition next
+**Status:** Active — I.8a–I.8b complete; I.8c terminal start next
 
 **Parent:** `2026-07-22-gamewindow-slice-8-checkpoint-i-ordered-composition.md`
 
@@ -81,6 +81,16 @@ Phase-7 suffix in reverse order.
 
 ## 3. I.8b — atomic frame-root composition
 
+**Completed 2026-07-22.** `FrameRootCompositionPhase` now constructs the
+unchanged render and update graphs from explicit prior-phase results and
+focused runtime owners. `GameFrameGraphSlot.PublishOwned` publishes and
+withdraws one exact pair. Optional lifecycle automation has a Phase-8 binding
+owner, and `WorldLifecycleResourceSnapshotSource` samples the same canonical
+owners without window callbacks or mirrored counters. The Phase-8 contract now
+receives the Phase-2 content result explicitly because scripts and particles
+are real frame dependencies; this removes a hidden reach-back through the
+window shell.
+
 Add `FrameRootCompositionPhase` implementing the existing
 `IFrameRootCompositionPhase` contract. Its dependencies are focused App owners;
 prior phase results supply all resources created during startup.

docs/plans/2026-07-22-gamewindow-slice-8-composition-lifecycle.md

@@ -29,8 +29,8 @@ audit.
 - [x] H — give terrain atlas, sky shader, retained `UiHost`, and both frame roots
   explicit single ownership and transfer seams.
 - [ ] I — group `OnLoad` into small ordered, fakeable composition phases with
-  transactional partial-acquisition rollback. I.1–I.7 and I.8a are complete;
-  I.8b atomic frame-root publication is active. Detailed plan:
+  transactional partial-acquisition rollback. I.1–I.8b are complete; I.8c
+  terminal session start is active. Detailed plan:
   [`2026-07-22-gamewindow-slice-8-checkpoint-i-ordered-composition.md`](2026-07-22-gamewindow-slice-8-checkpoint-i-ordered-composition.md).
 - [ ] J — move the exact retryable shutdown manifest to a focused lifetime
   owner and prove all partial-load/reentrant/retry paths.