Merge remote-tracking branch 'origin/master' into stack/agent-profiles-1-seam

# Conflicts:
#	docs/capability-seams.md
#	docs/event-producer-consumer.md
#	packages/README.i18n.yaml
#	packages/ui/app-boot/README.i18n.yaml
#	packages/ui/app-boot/src/index.ts
#	scripts/doc-budgets.manifest.json

packages/ui/app-boot/README.md

@@ -8,6 +8,7 @@ Shared boot glue for the app bins ([`dsh`](../../../apps/cli/README.md), [`dsh-c
 |---|---|
 | `resolveConfigPath(path, snapshotMode, cwd?)` | Absolute config path; `snapshotMode === 'replay'` swaps a `cordis.yml`/`.yaml` basename for its sibling `cordis.snapshot.yml` |
 | `loadEnv(binName, dir?, warn?)` | Load the gitignored `.env` (Node `process.loadEnvFile`); absent file is fine, an unloadable one warns a single labelled line (default: stderr) |
+| `loadLayeredEnv(binName, cwd?, warn?)` | Build the product CLI's frozen inherited > project `.env` > user `.env` snapshot, reject bootstrap-only file variables, and materialize accepted file values without replacing inherited ones |
 | `installFailLoud(binName, proc?, release?)` | Turn an unhandled boot or later Loader rejection into one labelled stderr line + `exit(1)`; the optional `release` teardown is awaited between the two (bounded by `FAIL_LOUD_RELEASE_TIMEOUT_MS`) so a terminal-owning surface restores the terminal before exit; returns the uninstaller |
 | `FAIL_LOUD_RELEASE_TIMEOUT_MS` | How long `installFailLoud` waits for its `release` hook; a wedged disposer delays the fatal exit, never cancels it |
 | `assertEntriesLoaded(ctx, binName)` | Throw when a settled tree holds an enabled entry with no fiber, reporting every unresolved plugin name as a Cordis startup failure |
@@ -38,7 +39,7 @@ A profile is a directory under `$DSH_HOME/profiles/<name>` (the Harness home res
 
 User-level machine-local preferences also live in the Harness home:
 
-- **`.env`** — the credential store of [`dsh-credentials-local`](../../credentials/credentials-local/README.md), read by that provider alone. No surface hoists it into `process.env`: doing so would make every stored key look like a read-only launch override on the next run, blocking rotation from the Web settings page. The environment layers are the ambient one and the invoking directory's `.env` (loaded by the bin; `process.loadEnvFile` never overrides), and a composition without the credential provider keeps resolving keys from those alone.
+- **`.env`** — the product CLI's ordinary environment layers: the invoking directory's file outranks the Harness-home file, and both sit below the inherited environment. `loadLayeredEnv` snapshots each value's source, rejects [bootstrap-only file variables](../../../.agents/notes/implemented/architecture/2026-08-04-configuration-source-ownership.md#decision) case-insensitively, and materializes accepted values into `process.env` for Loader expressions and third-party libraries. Managed credentials live separately in [`.credentials.yaml`](../../credentials/credentials-local/README.md); a credential left in either `.env` remains a lower-priority fallback.
 - **`cordis.patch.yml`** (home level) and **`profiles/<name>/cordis.patch.yml`** — the user patch layers, applied after every bundle layer (per-profile first, then the home-level file, which therefore outranks it): an id-targeted patch replaces the named entry's whole `config` (restate unchanged fields), `insert` adds entries, and `!!js` expressions interpolate at mount. A patch naming an entry id absent from the composed tree is a stderr warning. An empty or comments-only file throws (it parses to nothing, not to a list); disable the layer with `[]`.
 
 Long-lived surfaces keep `cordis.patch.yml` live through `watchUserPatches`; one-shot runs read only the startup value. The watcher targets the exact path even when the file or immediate parent does not exist, serializes bursts, and recomposes the user patches inside the caller's layer order (bundle layers below, overlay/flag patches above). A rejected read, parse, or Loader candidate leaves the last good tree running and the HMR service broadcasts `hmr/config-update-failed(filename, Error)` after logging it; observer failures are contained. Disposing the context closes the watcher and drains an active refresh.
@@ -55,5 +56,5 @@ No direct invalidation from `boot()`; a consumer that calls `addHarnessSourceSec
 
 - **Bare package specifiers depend on Loader internals** — production bins need Loader's optional native helper; an in-process caller without it must use resolvable relative/file specifiers or provide its own module-resolution hook.
 - **Snapshot replay swapping is basename-specific** — only a config ending in `cordis.yml` or `cordis.yaml` maps to the sibling `cordis.snapshot.yml`; custom config names require caller-managed selection.
-- **Environment loading is cwd-scoped and optional** — the helper loads one `.env` file and warns on failure; it does not search parents, merge profiles, or validate required variables.
+- **Environment discovery is launch-scoped** — `loadLayeredEnv` reads only the invocation directory and Harness home once; it does not search parents or follow a workspace selected later. `loadEnv` remains the one-directory helper for non-product bins.
 - **User patch layers are patch-shaped** — an id-targeted patch replaces the entry's whole `config` rather than deep-merging, so a profile override restates the bundle fields it keeps.