Add document standards, quality gates, and templates for team lifecycle phases

- Introduced `document-standards.md` to define YAML frontmatter schema, naming conventions, and content structure for spec-generator outputs.
- Created `quality-gates.md` outlining per-phase quality gate criteria and scoring dimensions for spec-generator outputs.
- Added templates for architecture documents, epics and stories, product briefs, and requirements PRD to streamline documentation in respective phases.

.claude/skills/team-executor/roles/executor/role.md

@@ -23,7 +23,7 @@ Orchestrate the team-executor workflow: session validation, state reconciliation
 ### MUST NOT
 - Execute task work directly (delegate to workers)
 - Modify task output artifacts (workers own their deliverables)
-- Call implementation subagents (code-developer, etc.) directly
+- Call CLI tools or spawn utility members directly for implementation (code-developer, etc.)
 - Generate new role-specs (use existing session role-specs only)
 - Skip session validation
 - Override consensus_blocked HIGH without user confirmation

.claude/skills/team-executor/specs/session-schema.md

@@ -163,7 +163,7 @@ team-executor validates the following before execution:
       "responsibility_type": "<type>",
       "inner_loop": false,
       "role_spec_metadata": {
-        "subagents": [],
+        "additional_members": [],
         "message_types": {
           "success": "<prefix>_complete",
           "error": "error"