fix(compile): drop archived pages from taken topics and the collision gate

src/vouch/compile.py

@@ -31,7 +31,7 @@
 from . import llm_draft
 from .config_coerce import coerce_bool
 from .context import _RETRACTED_CLAIM_STATUSES
-from .models import ProposalStatus
+from .models import Page, PageStatus, ProposalStatus
 from .proposals import ProposalError, _slugify, propose_page
 from .storage import ArtifactNotFoundError, KBStore
 
@@ -190,6 +190,19 @@ def to_dict(self) -> dict[str, Any]:
         }
 
 
+def _live_pages(store: KBStore) -> list[Page]:
+    """Pages the wiki still has, i.e. everything but the archived ones.
+
+    Archiving is how an operator retires a bad compile page. Counting an
+    archived page as taken makes that retirement one-way: the LLM is told not
+    to redraft a topic the wiki no longer carries, and a draft that reuses the
+    title is dropped as a duplicate of a page nobody can read. Claims already
+    get this treatment via `_RETRACTED_CLAIM_STATUSES`; this is the same live
+    set recall, digest, search and the wiki view use.
+    """
+    return [p for p in store.list_pages() if p.status is not PageStatus.ARCHIVED]
+
+
 def _pending_page_names(store: KBStore) -> set[str]:
     """Lowercased titles + ids of page proposals already awaiting review."""
     names: set[str] = set()
@@ -285,7 +298,7 @@ def build_prompt(
     ]
     if not claims:
         raise CompileError("nothing to compile: the KB has no live approved claims")
-    pages = store.list_pages()
+    pages = _live_pages(store)
     pending = _pending_page_names(store)
 
     lines = [
@@ -472,7 +485,7 @@ def compile_kb(
 
     report = CompileReport(drafts=drafts, dry_run=dry_run)
 
-    existing = store.list_pages()
+    existing = _live_pages(store)
     taken_names = {p.title.strip().lower() for p in existing}
     taken_names |= {p.id.strip().lower() for p in existing}
     taken_names |= _pending_page_names(store)

tests/test_compile.py

@@ -689,3 +689,73 @@ def test_two_phase_compile_drafts_planned_pages(
     cmd = _phased_stub(tmp_path, topics, drafts)
     report = compile_kb(store, config=_cfg(cmd, two_phase=True))
     assert [r["title"] for r in report.proposed] == ["Retry Policy"]
+
+
+# --- archived pages are retired, not permanently taken (#700) ---------------
+
+
+def _archived_page(store: KBStore, page_id: str, title: str) -> None:
+    from vouch.models import Page, PageStatus
+
+    store.put_page(
+        Page(id=page_id, title=title, body="old", status=PageStatus.ARCHIVED)
+    )
+
+
+def test_archived_pages_are_not_listed_as_taken_topics(store: KBStore) -> None:
+    """Regression for #700: an archived topic stayed in TAKEN TOPICS forever,
+    so the LLM was told never to redraft a page the wiki no longer carries."""
+    _approved_claim(store, "the retry limit is three attempts")
+    _archived_page(store, "retry-policy", "Retry Policy")
+
+    prompt = compile_mod.build_prompt(store, max_pages=3)
+    assert "retry-policy: Retry Policy" not in prompt
+    assert "- (none)" in prompt
+
+
+def test_live_pages_are_still_listed_as_taken_topics(store: KBStore) -> None:
+    from vouch.models import Page
+
+    _approved_claim(store, "the retry limit is three attempts")
+    store.put_page(Page(id="live-policy", title="Live Policy", body="current"))
+
+    prompt = compile_mod.build_prompt(store, max_pages=3)
+    assert "live-policy: Live Policy" in prompt
+
+
+def test_a_draft_may_reuse_an_archived_title(
+    store: KBStore, tmp_path: Path
+) -> None:
+    """The other half of #700: the collision gate dropped a draft that reused
+    an archived title, so archiving a bad page made that topic unwritable."""
+    c1 = _approved_claim(store, "the retry limit is three attempts before failing")
+    _archived_page(store, "retry-policy", "Retry Policy")
+
+    cmd = _stub_llm(tmp_path, [{
+        "title": "Retry Policy",
+        "type": "decision",
+        "body": f"Rewritten from scratch [claim: {c1}]",
+        "claims": [c1],
+    }])
+    report = compile_kb(store, config=_cfg(cmd))
+    assert [r["title"] for r in report.proposed] == ["Retry Policy"]
+    assert report.dropped == []
+
+
+def test_a_draft_reusing_a_live_title_is_still_dropped(
+    store: KBStore, tmp_path: Path
+) -> None:
+    from vouch.models import Page
+
+    c1 = _approved_claim(store, "the retry limit is three attempts before failing")
+    store.put_page(Page(id="retry-policy", title="Retry Policy", body="current"))
+
+    cmd = _stub_llm(tmp_path, [{
+        "title": "Retry Policy",
+        "type": "decision",
+        "body": f"Would collide [claim: {c1}]",
+        "claims": [c1],
+    }])
+    report = compile_kb(store, config=_cfg(cmd))
+    assert report.proposed == []
+    assert len(report.dropped) == 1