docs: split LLM project workflow into task-specific modes (Closes #333)

Consolidate all four canonical workflow files and router SKILL.md:
- review-merge-pr.md (from #334 canonical prompt)
- reconcile-landed-pr.md (reconciliation gates + handoff schema)
- create-issue.md (canonical issue-creation prompt)
- work-issue.md (canonical author/coder prompt)

SKILL.md is now a short router with mode isolation and universal rules.
Adds final-report schemas for all modes and 13 doc-contract tests.

Supersedes partial split work in PR #335; full #333 acceptance in one PR.

tests/test_llm_workflow_split.py

@@ -3,43 +3,96 @@ from pathlib import Path
 
 REPO_ROOT = Path(__file__).resolve().parent.parent
 SKILL_DIR = REPO_ROOT / "skills" / "llm-project-workflow"
+SKILL = (SKILL_DIR / "SKILL.md").read_text(encoding="utf-8")
 
 
-def test_work_issue_workflow_file_exists():
-    path = SKILL_DIR / "workflows" / "work-issue.md"
-    text = path.read_text(encoding="utf-8")
+def test_skill_md_exists():
+    assert SKILL_DIR.joinpath("SKILL.md").is_file()
+
+
+def test_all_workflow_files_exist():
+    for name in (
+        "review-merge-pr.md",
+        "reconcile-landed-pr.md",
+        "create-issue.md",
+        "work-issue.md",
+    ):
+        assert (SKILL_DIR / "workflows" / name).is_file(), name
+
+
+def test_skill_references_all_workflow_files():
+    for name in (
+        "workflows/review-merge-pr.md",
+        "workflows/reconcile-landed-pr.md",
+        "workflows/create-issue.md",
+        "workflows/work-issue.md",
+    ):
+        assert name in SKILL
+
+
+def test_skill_contains_mode_isolation_language():
+    assert "## Mode isolation" in SKILL
+    assert "review-merge-pr" in SKILL
+    assert "reconcile-landed-pr" in SKILL
+    assert "create-issue" in SKILL
+    assert "work-issue" in SKILL
+    assert "Do not mix modes" in SKILL or "do not mix modes" in SKILL.lower()
+
+
+def test_skill_is_router_not_monolithic_review_body():
+    assert "This skill is a **router**" in SKILL or "router" in SKILL.lower()
+    assert "## F. Review workflow" not in SKILL
+    assert "gitea_mark_final_review_decision" not in SKILL
+    assert "gitea_submit_pr_review" not in SKILL
+
+
+def test_review_merge_workflow_contract():
+    text = (SKILL_DIR / "workflows" / "review-merge-pr.md").read_text(encoding="utf-8")
     assert "canonical: true" in text
-    assert "work-issue" in text
-    assert "## 0. Load the canonical workflow first" in text
-    assert "## 29. Controller handoff schema" in text
-    assert "## 30. Stop conditions summary" in text
-    assert "ISSUE_ELIGIBILITY_UNVERIFIED" in text
-    assert "OPEN_PR_EXISTS" in text
-    assert "author/coder workflow" in text.lower()
+    assert "## 26A. Terminal review mutation hard-stop" in text
+    assert "## 11A. Skipped PRs are read-only" in text
+    assert "## 35. Duplicate request-changes prevention" in text
+    assert "ALREADY_LANDED_RECONCILE_REQUIRED" in text
 
 
-def test_work_issue_final_report_schema_exists():
-    path = SKILL_DIR / "schemas" / "work-issue-final-report.md"
-    text = path.read_text(encoding="utf-8")
-    assert "Controller Handoff" in text
-    assert "Issue inventory pagination proof:" in text
-    assert "File edits by author:" in text
-    assert "Workspace mutations" in text  # documented as rejected
+def test_reconcile_landed_workflow_contract():
+    text = (SKILL_DIR / "workflows" / "reconcile-landed-pr.md").read_text(encoding="utf-8")
+    assert "canonical: true" in text
+    assert "Do not review or merge normal PRs" in text
+    assert "Already-landed proof" in text
 
 
-def test_skill_router_points_to_work_issue_workflow():
-    skill = (SKILL_DIR / "SKILL.md").read_text(encoding="utf-8")
-    assert "## Task mode router" in skill
-    assert "workflows/work-issue.md" in skill
-    assert "schemas/work-issue-final-report.md" in skill
-    assert "Identify task mode before any mutation" in skill
+def test_create_issue_workflow_contract():
+    text = (SKILL_DIR / "workflows" / "create-issue.md").read_text(encoding="utf-8")
+    assert "canonical: true" in text
+    assert "## 9. Duplicate search before mutation" in text
 
 
-def test_skill_still_declares_controller_handoff_contract():
-    skill = (SKILL_DIR / "SKILL.md").read_text(encoding="utf-8")
-    assert "## Controller Handoff" in skill
-    assert "assess_controller_handoff" in skill
-    assert "## Global LLM Worktree Rule" in skill
+def test_work_issue_workflow_contract():
+    text = (SKILL_DIR / "workflows" / "work-issue.md").read_text(encoding="utf-8")
+    assert "canonical: true" in text
+    assert "Do not merge your own PR" in text
+    assert "## 21. PR creation rules" in text
+
+
+def test_final_report_schemas_exist():
+    for name in (
+        "review-merge-final-report.md",
+        "reconcile-landed-final-report.md",
+        "create-issue-final-report.md",
+        "work-issue-final-report.md",
+    ):
+        assert (SKILL_DIR / "schemas" / name).is_file(), name
+
+
+def test_review_pr_template_references_workflow():
+    text = (SKILL_DIR / "templates" / "review-pr.md").read_text(encoding="utf-8")
+    assert "workflows/review-merge-pr.md" in text
+
+
+def test_merge_pr_template_references_workflow():
+    text = (SKILL_DIR / "templates" / "merge-pr.md").read_text(encoding="utf-8")
+    assert "workflows/review-merge-pr.md" in text
 
 
 def test_start_issue_template_references_work_issue_workflow():