docs(config): align environment and credential contracts

Code already treats $DSH_HOME/.env as ordinary launch environment and stores managed credentials in .credentials.yaml, but public docs still described the old store, old precedence, removed literal adapter keys, and the deleted TUI. That directed users to the wrong file and overstated the supported configuration surface.

Update the existing English and Chinese owners in place, document inherited > managed > project > user credential resolution, and record the loadLayeredEnv export. Regenerate only pairing records and the source-line catalog; add no new section or site route.

.agents/notes/implemented/architecture/2026-08-04-configuration-source-ownership.md

@@ -40,7 +40,7 @@ inherited process environment      (read-only, wins)
 
 The launching environment wins because `DEEPSEEK_API_KEY=… dsh`, a CI secret, and a container `-e` are the one override an operator must be able to apply per run without editing machine state, and because it cannot be edited from inside it must be *visibly* read-only. Configuration is meant to carry only the *reference* — which name to resolve — and that name follows the non-secret ordering above.
 
-**The project the harness is launched in is trusted, by default and without a prompt.** A checkout may carry its own endpoint, its own ordinary variables, and its own key; the key ranks below the managed store, so a key stored through the web page or TUI is never displaced by one a checkout happens to contain. `EnvironmentSnapshot.getFrom(name, sources)` still searches only the layers a caller names, and omitting one is a refusal rather than a demotion — the mechanism exists for the decisions where a layer must be unreachable, not because the project is one of them today.
+**The project the harness is launched in is trusted, by default and without a prompt.** A checkout may carry its own endpoint, its own ordinary variables, and its own key; the key ranks below the managed store, so a key stored through the Models page is never displaced by one a checkout happens to contain. `EnvironmentSnapshot.getFrom(name, sources)` still searches only the layers a caller names, and omitting one is a refusal rather than a demotion — the mechanism exists for the decisions where a layer must be unreachable, not because the project is one of them today.
 
 **Trust does not extend to changing the harness itself.** `isBootstrapOnly` rejects, at load and before anything is materialized, any `.env` that sets a variable governing how a process launches (`PATH`, `SHELL`, `NODE_OPTIONS`, `LD_PRELOAD`), what code a runtime executes before the program it was asked to run (`BASH_ENV`, `PERL5OPT`, `PYTHONSTARTUP`, `RUBYOPT`, `JAVA_TOOL_OPTIONS`, the Git hook commands), where model-visible instructions load from (the whole `DSH_*` namespace, `HOME`, `XDG_*`), or how the network is reached and trusted (proxy and CA variables). Matching is case-insensitive, so `https_proxy` is not a bypass.
 
@@ -55,7 +55,7 @@ The line is that these take effect with no user action, before any turn, outside
 - The web credential form now takes effect against an older key in the user's `.env`; only a key exported in the launching shell still makes it read-only, and the diagnostic says so.
 - A `.env` holding `DSH_*`, `PATH`, or a proxy variable fails the launch instead of being applied. Developers keeping switches in a repository `.env` move them to their shell — a deliberate, loud break.
 - Composition is no longer overridable by a stale shell endpoint. It is still overridable by a user's stored `settings.yaml`, which is the settings seam's layering and not something this note changes; the product CLI offers no flag above it, so a deployment that must win against stored settings owns its own bin or loader tree.
-- Not solved: the layers are still materialized into `process.env`, so ordinary project variables continue to reach child processes under the subprocess scrub. Bootstrap variables cannot come from a file at all, which closes the escalation path; a project `.env` setting something like `GIT_SSH_COMMAND` for the tools an agent runs remains possible and is recorded as a limitation on the package.
+- Not solved: the layers are still materialized into `process.env`, so ordinary project variables continue to reach child processes under the subprocess scrub. Bootstrap variables cannot come from a file at all; the environment package records the remaining subprocess reach as a limitation.
 - The LLM adapters no longer accept a literal `apiKey`: configuration carries the reference and nothing else, so a settings document cannot become a second credential store. No adapter namespace is strict, so writing one is dropped rather than rejected. The web-search providers still declare a `role('secret')` literal key; they register no settings namespace, so nothing can shadow a stored credential through them, but the claim is about the adapters rather than the repository as a whole.
 - Exa and Perplexity still capture their key at load time rather than through the credential seam. They no longer read raw `process.env` — they resolve through the trusted layers — but converting them to per-request seam resolution is separate work.