fix(acp): server crashed on connect — drop export default, read optional service cwd-independently

Two independent bugs made the ACP server crash the moment an editor (Zed)
connected, despite 178 green unit tests at 100% coverage:

1. `session/new` threw `cannot get property "agents" without inject`. Root
   cause: a stray `export default apply` made the cordis Loader's
   `unwrapExports` (`exports.default ?? exports`) collapse the module to the
   bare `apply` function, discarding the sibling `inject`/`name`/`Config`
   named exports. The plugin fiber was built with empty `inject`, so every
   `ctx.<service>` read in `apply` threw at load. Fix: remove the default
   export so the Loader uses the namespace.

2. `session/load` threw `cannot get property "sessionPersistence" without
   inject`. `AgentLoop.resume` read `this.ctx.sessionPersistence` (a service
   it deliberately does NOT inject); the property proxy's ancestor-only fiber
   walk fails through the bridge's traceable shadow. Fix: read it via
   `this.ctx.get('sessionPersistence', false)`, the topology-independent
   global-store lookup.

Why the suite missed both: every test mounted the plugin by hand
(`ctx.plugin({name,inject,apply})`), bypassing `unwrapExports` entirely, and
the only test driving these RPCs was key-gated (skipped in CI). Added a no-key
`session/new` e2e that boots the real example through the real Loader — it
fails loudly on bug #1 without an API key. Set `TSX_TSCONFIG_PATH` in the e2e
spawn so the subprocess resolves workspace `paths` from a temp cwd (it was
silently falling back to a stale built `lib/`).

Docs: post-mortem 0001; AGENTS.md "line coverage is not behavior coverage" +
with-key/smoke-test philosophy; packages/AGENTS.md plugin-export-shape and
ctx.get rules; dsh-code-review SKILL checks.

.agents/skills/dsh-code-review/SKILL.md

@@ -20,8 +20,9 @@ This is a where-to-look map, not a rules list. The rules live in the docs below
 1. **Docs in sync?** If the PR changes a config key, default, error code, wire field, or event name, did it update the package README + module/JSDoc in the same diff? Stale docs are the most common miss — `pnpm run doc-sync` only gates compilable `ts` blocks and the event-taxonomy table, so prose drift (config keys, defaults, error codes, wire fields) has no gate and is on the reviewer to catch.
 2. **HMR-safety test present?** Any new registry/registration needs a test that disposes the contributing fiber and asserts cleanup. Its absence is a blocking gap.
 3. **Gates green?** typecheck, lint, test, test:coverage (100% per-file on `packages/*/src`), knip, build, publint, constraints. Don't re-review what a gate already enforces — trust the gate, spend attention on what gates can't check (intent, contracts, doc sync).
-4. **e2e verifies the world, not the agent's self-report.** For real-API tests, confirm the assertion re-runs the command/checks the file externally — a keyword probe lets a cheating agent pass (see AGENTS.md e2e bullet).
-5. **Seam discipline.** New swappable capability? Check it's split per ADR 0009 (interface / impl / consumer), and that the consumer injects the interface key, never an implementation type.
+4. **e2e verifies the world, not the agent's self-report.** For real-API tests, confirm the assertion re-runs the command/checks the file externally — a keyword probe lets a cheating agent pass (see AGENTS.md e2e bullet). For a behavior change to the agent's real flows, a no-key/mock test alone is usually insufficient: a with-key e2e (especially a smoke test that boots the real example and checks the world) is cheap here and catches "green units, broken product" — encourage it rather than treating real-API tests as expensive (see AGENTS.md § Secrets / .env).
+5. **Plugin export shape + real-loader coverage.** A new/changed `cordis.yml`-loaded plugin: is it a function/namespace plugin (`name`/`inject`/`Config`/`apply` named exports) with NO `export default`? A stray default export makes the Loader's `unwrapExports` drop `inject` and the plugin crashes at load with `cannot get property … without inject` — invisible to hand-built `ctx.plugin({...})` tests and to line coverage. Confirm there's a test driving it through the REAL loader path (the no-key subprocess e2e for ACP is the model). And any opportunistic read of a service NOT in `static inject` should use `ctx.get(name, false)`, not `ctx.<name>` (the property proxy throws through a foreign shadow). See [packages/AGENTS.md](../../../packages/AGENTS.md), AGENTS.md § Defensive patterns, and [docs/postmortem/0001](../../../docs/postmortem/0001-acp-default-export-drops-inject.md).
+6. **Seam discipline.** New swappable capability? Check it's split per ADR 0009 (interface / impl / consumer), and that the consumer injects the interface key, never an implementation type.
 
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