Stabilize packaged release build graph

notes/epiphany-current-algorithmic-map.md

@@ -1923,3 +1923,25 @@ vendored Starlark's older `hashbrown` integration; Rust rejected the missing
 release-target check traversing Starlark through Codex login and
 `epiphany-openai-auth-spine` completed successfully in 3m16s. This is lockfile
 compatibility authority, not a source patch or relaxed gate.
+
+### Single deterministic packaged build authority
+
+The original packaged-release path invoked Cargo three times against one target
+directory: the broad root binary graph, the coordinator feature graph, and the
+core-owned state steward. Cargo correctly rebuilt when each command changed the
+selected feature set, so the cache oscillated instead of warming. Exact source
+`e9465c11` took 24m22s cold (17m03s root plus 6m38s state) and 28m30s on an
+identical cached rerun (21m04s root, 34.62s coordinator, 6m42s state).
+
+The two runs also yielded different valid authenticated releases. Twenty-one of
+23 binaries were byte-identical; only the two `epiphany-openai-runtime`
+binaries differed, including different ELF build IDs and code bytes. Release
+incremental codegen is therefore not an admissible input to witnessed output.
+
+`build_required_release_siblings` now has one process owner. It selects
+`epiphany-release-bundle` and `epiphany-core`, selects
+`epiphany-release-bundle/coordinator-runtime` once, names all 23 required
+binaries explicitly, and sets `CARGO_INCREMENTAL=0`. Follow-up coordinator and
+state-steward Cargo commands are forbidden writers and have been deleted. All
+19 focused packaged-release tests pass. Exact Linux packaging plus a
+byte-identical warm rerun remain the verification boundary.

notes/fresh-workspace-handoff.md

@@ -1,5 +1,37 @@
 # Fresh workspace handoff
 
+## Deterministic single release graph — 2026-08-09
+
+Exact pushed source `e9465c11208d648440999903770cbde245c1da3b`
+produced authenticated release
+`sha256-5f90294fb037ff777ca99f345e0f4b1e082b176c35bd6e16a60b46d5a687c0cb`
+with witness
+`sha256-403a4dd4705772d8d588f3abedb336436b9f1b4ebc037b86efbc5995f5d6a291`.
+Native inspection accepted the exact source and all 23 required binaries. The
+packaged `epiphany-state` hash is
+`8e5e0edd3af59a9f8710d4b6b3a7fbe8243f1002acd6e1d4c415e8053d0cd7c2`.
+
+The cold package took 24m22s: 17m03s for the root graph and 6m38s for the
+separate state-steward graph. The identical cached rerun was worse at 28m30s:
+21m04s for the root graph, 34.62s for the coordinator graph, and 6m42s for the
+state-steward graph. It also produced a different authenticated release,
+`sha256-4700e984410e0c8e735d1fcecec282235ed5d096d20b6dbbdb206a83636228fa`,
+with witness
+`sha256-f71519f7a27a9588715daf9f11d33031b2680659aa405c29807a39efcfcce373`.
+Twenty-one binaries were byte-identical; only `epiphany-model-runtime` and
+`epiphany-persona-service`, both from `epiphany-openai-runtime`, changed. The
+old packager was oscillating one target cache through three feature graphs,
+and incremental release codegen made the authenticated output nondeterministic.
+
+The source cut now uses one Cargo command for both first-party packages, the
+coordinator feature, and all 23 explicit binaries, with `CARGO_INCREMENTAL=0`.
+The separate coordinator and state-steward build authorities are deleted. All
+19 focused packaged-release tests pass. The cold Windows harness took 3m38s;
+the final source rerun compiled in 47.87s and executed in 0.83s. Commit and push
+this cut, then require an exact Linux package and an identical warm rerun with
+both materially improved time and exact release/witness equality before
+publication.
+
 ## Unified Cargo authority and shipped state steward — 2026-08-09
 
 The first exact `6808f3f5` package attempt failed before release construction: