docs: fix review findings — support-group summary row, smoke-prose export-shape claims

The packages/README.md group table still described support/ as holding
the stdio UI; and three prose sites credited the keyless smokes with
guarding the app export shape, which a bundle without inject cannot do
(a stray default boots rather than crashes) — the shape is pinned by
the stdio-agent unit suite's explicit unwrapExports assertion; the
smokes prove the composed tree boots.

examples/echo-agent/tests/echo.e2e.ts

@@ -14,10 +14,11 @@ import { afterEach, describe, expect, it } from 'vitest'
  * This is the guard the per-file unit suite structurally cannot be: it drives
  * the `@deepseek-ai/dsh-stdio-agent` app plugin, the `@deepseek-ai/dsh-agent-core`
  * bundle it loads, the app's in-package readline UI module, AND the
- * example-local `mock-llm.ts` / `echo-tool.ts` through their REAL load path, so
- * a broken plugin export shape (a stray `export default` that `unwrapExports`
- * would collapse, dropping `inject`/`Config`) fails here even though hand-mounted
- * unit tests stay green (see docs/postmortem/0001). It needs no API key — the
+ * example-local `mock-llm.ts` / `echo-tool.ts` through their REAL load path
+ * (see docs/postmortem/0001). The app itself carries no `inject`, so a stray
+ * `export default` would boot rather than crash here — the export SHAPE is
+ * pinned by the explicit unwrap assertion in the stdio-agent unit suite; this
+ * smoke proves the composed tree actually runs. It needs no API key — the
  * `mock-echo` adapter never touches the network — so it runs in the default e2e
  * gate.
  *