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>

TEAM.yaml

@@ -249,7 +249,6 @@ skills:
       applies_to:
         - claude
         - codex
-        - opencode
       install_mode: shared
     qa-checklist:
       id: qa-checklist
@@ -275,7 +274,6 @@ skills:
 rules:
   order:
     - 01-session
-    - 02-responses
     - 03-git
     - 04-tools
     - 05-verification
@@ -286,15 +284,6 @@ rules:
       source_file: rules/01-session.md
       applies_to:
         - claude
-        - codex
-        - opencode
-    02-responses:
-      id: 02-responses
-      source_file: rules/02-responses.md
-      applies_to:
-        - claude
-        - codex
-        - opencode
     03-git:
       id: 03-git
       source_file: rules/03-git.md