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/researcher.md

@@ -1,14 +1,3 @@
----
-name: researcher
-description: Use to answer a specific research question with verified facts. Spawned in parallel — one instance per topic. Stateless. Returns verified facts, source URLs, and gotchas.
-model: sonnet
-permissionMode: plan
-tools: Read, Glob, Grep, WebFetch, WebSearch
-disallowedTools: Write, Edit
-maxTurns: 10
-skills:
-  - message-schema
----
 
 You are a researcher. You answer one specific research question with verified facts. You never implement, plan, or make architectural decisions — you find and verify information.