fix(recall): archived page titles leak into every session-start digest

[boskodev790]

recall.build_digest filters claims by status but not pages. an archived page's title is injected into the opening context of every new session, while its claims are correctly suppressed.

where — src/vouch/recall.py:57-61:

claims = [
    c for c in store.list_claims()
    if c.status not in _RETRACTED_CLAIM_STATUSES
]
pages = store.list_pages()          # <- no status filter

Page.status exists (models.py:337) and synthesize.py:121,124 already filters page.status != PageStatus.ARCHIVED, so recall is the odd surface out.

why it matters — the rationale is already written down on _RETRACTED_CLAIM_STATUSES (context.py:35): "otherwise the archive/supersede/redact controls are decorative." that argument applies to pages. recall is also the one surface that runs unprompted on every SessionStart, so a retracted title reaches every future session's first turn.

repro — archiving a page means setting status: archived in its frontmatter (the plaintext / obsidian edit path; lifecycle.archive is claims-only). the status round-trips through get_page correctly:

s = KBStore.init(Path("kb"))
pr = propose_page(s, title="obsolete design", body="body", proposed_by="a")
pg = approve(s, pr.id, approved_by="u")
p = s._page_path(pg.id)
p.write_text(p.read_text().replace("status: draft", "status: archived"))

assert s.get_page(pg.id).status is PageStatus.ARCHIVED    # passes
assert "obsolete design" not in recall.build_digest(s)    # fails on test

scope — only ARCHIVED should be filtered. DRAFT and STALE stay live knowledge, mirroring the reasoning that keeps CONTESTED in the claim set.

happy to send the fix.