fix(docs): address Codex review round 2 — repoint every remaining moved-policy citation

The definitive sweep (audit every AGENTS.md mention in packages/, docs/,
examples/, scripts/) found thirteen more citations of relocated policy
and two citations of rules that never existed as quoted:

- with-key policy comments (web deepseek/perplexity e2e headers) ->
  docs/testing.md; real-impl-over-mock comments (acp harness, load,
  stream-update specs) -> docs/testing.md; defensive-pattern quotes
  (acp index.ts x3, stream-update) -> docs/defensive-patterns.md.
- md-tier repoints: real-api-e2e RFC, tool-schema-catalog RFC,
  postmortem 0001 guardrail row, adding-a-package cookbook,
  drop-bash-output-spill-files RFC, acp-subagent-backend RFC phrasing.
- Two false attributions dropped in favor of self-contained reasoning:
  tool-todo's 'don't validate scenarios that can't happen' and the
  bash-stdin-env RFC's 'Don't add features beyond what the task
  requires' (neither rule ever existed under those names).
- Citations of the two 'not golden truth' doctrines stay: those bullets
  survive verbatim in the root conventions.

Note: packages/support/ui-stdio readline TTY spec flakes under full
coverage on a heavily loaded box (passes standalone and passed the
same tree's coverage run minutes earlier); untouched by this stack.

docs/rfc/implemented/architecture/2026-06-30-bash-stdin-env-trusted-plugin-surface.md

@@ -26,7 +26,7 @@ Three deliberate choices:
 
 ## Scope: configurable scrub pattern is NOT included
 
-An earlier sketch of this work also proposed making `SENSITIVE_ENV_PATTERN` configurable. Validating against the code, that is **speculative and already subsumed**: `run.ts` documents a configurable whitelist as future work, and the new explicit `env` field — merged after the scrub — already gives a caller full control, including over credential-shaped vars. There is no current caller that needs to *broaden* the ambient scrub (the hazard runs the other way). Adding a config knob now would be a feature with no consumer, against [AGENTS.md](../../../../AGENTS.md) § "Don't add features beyond what the task requires". If a real workflow ever needs to forward a specific ambient credential, the explicit `env` field is the supported path; a configurable scrub can be reconsidered then.
+An earlier sketch of this work also proposed making `SENSITIVE_ENV_PATTERN` configurable. Validating against the code, that is **speculative and already subsumed**: `run.ts` documents a configurable whitelist as future work, and the new explicit `env` field — merged after the scrub — already gives a caller full control, including over credential-shaped vars. There is no current caller that needs to *broaden* the ambient scrub (the hazard runs the other way). Adding a config knob now would be a speculative surface with no consumer. If a real workflow ever needs to forward a specific ambient credential, the explicit `env` field is the supported path; a configurable scrub can be reconsidered then.
 
 ## Consequences