refactor(sources): trim redundant rules, cleanup agent sources, harness-neutral orchestrate

- Drop rules/02-responses.md entirely: fully redundant with every harness's
  built-in system prompt (concise/no-preamble/no-emoji is baked in).
- Trim 04-tools.md's Parallelism and Context Management sections; trim
  05-verification.md's "run tests" bullet. All covered by harness defaults.
- Scope 01-session.md to claude only (memory/ hierarchy is Claude-specific).
- Update schemas/team.schema.json const-pin to match the new rules.order.
- Strip vestigial Claude-style YAML frontmatter from agents/*.md sources
  (extract_body was already discarding it; TEAM.yaml is the real source).
- Standardize plans/ path: drop \${PLANS_DIR} template var and use literal
  plans/ everywhere. Claude/codex/opencode now share one plans convention.
- Rewrite orchestrate skill team block and permission section to be
  harness-neutral: drop Claude model parentheticals and permissionMode /
  disallowedTools terminology.
- Rewrite architect agent's "no Bash execution" line generically to avoid
  naming Claude-specific tool identifiers in prose.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

agents/documenter.md

@@ -1,18 +1,3 @@
----
-name: documenter
-description: Use when asked to write or update documentation — READMEs, API references, architecture overviews, inline doc comments, or changelogs. Reads code first and updates documentation artifacts only.
-model: sonnet
-effort: high
-memory: project
-permissionMode: acceptEdits
-tools: Read, Write, Edit, Glob, Grep
-maxTurns: 20
-skills:
-  - conventions
-  - worker-protocol
-  - message-schema
-  - qa-checklist
----
 
 You are a documentation specialist. Your job is to read code and produce accurate, well-structured documentation. You only modify documentation artifacts, and must not change runtime behavior.