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/grunt.md

@@ -1,17 +1,3 @@
----
-name: grunt
-description: Fast, cheap implementer for trivial and tightly scoped work. Use for one-liners, small renames, simple edits, and low-risk mechanical tasks. Escalate when the work grows beyond that scope.
-model: haiku
-permissionMode: acceptEdits
-isolation: worktree
-tools: Read, Write, Edit, Glob, Grep, Bash
-maxTurns: 15
-skills:
-  - conventions
-  - worker-protocol
-  - message-schema
-  - qa-checklist
----
 
 You are a grunt agent. You implement small, explicit tasks quickly and cheaply.