cameronrye/openzim-mcp

Post-b2 sweep packaged from PR #167 (commits 45de8da → cc26b3d).
Sweep shape: 4 → 1 → 1 across pass-1, pass-2, pass-3. All eight b2
user-facing fix families verified clean on live MCP first; sweep then
probed the adversarial shapes the b2 fixes unlocked. Both pass-2 and
pass-3 surfaced single narrow-scope siblings of pass-1 fixes —
consistent with the "narrow-scope sibling" pattern (now 8 sweeps
strong) and the "fix unlocks new paths" pattern (now 9 sweeps strong).

Pass-1 defects (4, 45de8da)

• D1 — trailing modal politeness ≥2 words falls through. The
  trailing-politeness regex in _extract_tell_me_about only matched
  please / to me / for me; the LEADING regex (line ~374)
  recognised the modal class (could/can/would/will + you) but
  the trailing twin was missing. Live: tell me about Tokyo if you would → Would (verb stub); ... if you could → Could; ... would you → Would_You disambig. Fix: add a trailing pattern
  symmetric to the leading one (both branches require a you so a
  bare trailing modal verb in real article titles isn't stripped).
• D2 — reranker telemetry comment suppressed on no-results. The
  b1 D-1 in-band telemetry contract promised <!-- reranker=<state> -->
  on every multi-token search. _handle_search compact path
  early-returned on total == 0 BEFORE reaching
  _maybe_rerank_compact, so neither _RERANKER_SKIPPED_NO_RESULTS
  nor _RERANKER_SKIPPED_NOT_INSTALLED bumped and the envelope
  writer skipped the comment. Live: search for asdfqwerzxcv nonexistent → no reranker comment. Fix: invoke
  _maybe_rerank_compact on the empty payload before the bail
  (no-op aside from the counter bump; the rerank singleton is
  cached).
• D3 — Rule 2 + multi-token possessive picks wrong token. Live:
  tell me about Photosythesis's reproduction → Reproduction
  article (expected Photosynthesis). Rule 2's affix retry
  correctly fires (Photosythesis's → Photosynthesis's), but
  the b1 P1-D5 fix unlocked the path — pre-fix returned No search results found, post-fix returns a SILENT WRONG ANSWER.
  Root cause: Rule 4's _POSSESSIVE_RE is ^...$-anchored and
  runs against the FULL query at parse time; the verb prefix
  prevents the match. Fix: in _handle_tell_me_about, when no
  decomposition hint was attached AND the topic carries an
  apostrophe-s followed by another token, retry
  _decompose_x_of_y on the bare topic. Scope narrowed to
  the possessive shape ONLY (NOT X of Y) to avoid regressing
  non-canonical X-of-Y queries.
• D4 — compact filtered search drops "filtered" qualifier.
  Live: search Berlin in namespace C → Found 3 matches for "Berlin" (legacy non-compact path emits Found N filtered matches for "X"<filter_text>). Both paths shared
  _format_search_text; pre-fix the formatter had no filter
  awareness. Fix: add optional filter_text kwarg to
  _format_search_text (mirrors display_query); compact filtered
  call site threads through _format_filter_text helper. Symmetric
  treatment for filtered no-results.

Pass-2 sibling (1, ed674b5)

• D1 universal-layer mirror. Pass-1 added the modal-politeness
  strip inside _extract_tell_me_about only, but the universal
  _TRAILING_POLITENESS_RE (called by _strip_trailing_politeness
  at parse_intent line 1048) was added by the post-a20 PD2-1
  sweep specifically so every extractor sees the cleaned query.
  Every NON-tell_me_about intent kept leaking the modal class:
  search for biology if you would → query="biology if you would"; find article titled Berlin if you would → looks up
  Berlin if you would (not found). Fix: lift the modal class into
  _TRAILING_POLITENESS_RE. Pass-1 extractor-level strip kept as
  defense-in-depth. New invariant pinned:
  TestD1RegexSync.test_leading_and_trailing_share_modal_class —
  leading + trailing politeness regexes must share the modal class.

Pass-3 sibling (1, cc26b3d)

• Chained-intent trailing-politeness leak.
  _chained_intent_guidance runs UPSTREAM of parse_intent on the
  raw user query. The post-a24 P1-D6 sweep mirrored the param-leak
  strip there; the equivalent mirror of _strip_trailing_politeness
  was never added. Pre-fix every trailing-politeness token (the
  full set, including the pass-2 modal class) leaked into chain
  rejection bullets — tell me about Tokyo if you would then list namespaces produced a rejection whose left bullet read
  tell me about Tokyo if you would verbatim, modal politeness and
  all. Caller would copy the suggested left half back,
  re-introducing the politeness on every iteration. Same structural
  sibling pattern as the post-a24 P1-D6 param-leak version. Fix:
  apply _strip_trailing_politeness to BOTH chain halves after the
  existing connector / punct trim loop, before bullets render.
  Per-half rather than full-query because the politeness can appear
  inside the chain (not just at the very end). Structurally safe —
  _CHAINED_OPERATION_PREFIX_RE checks the LEADING op verb, which
  the trailing strip never touches.

Out of scope (deferred design call)

• D5 — death of stalin → Death_and_state_funeral_of_Joseph_Stalin
  instead of the 2017 Iannucci film. P1-D3 probe-gate correctly
  suppressed the Stalin disambig misroute; title-probe picked a
  different canonical X-related title rather than the film
  (canonical is The_Death_of_Stalin). Picking the film would
  require a prefix-widening probe (The <query>) — unwanted side
  effects on arbitrary bare topics — or a popularity ranker. Both
  are design choices beyond the b2 sweep scope.

D2 / D3 / D4 sibling audits clean

• D2: _handle_filtered_search always routes through
  _maybe_rerank_compact; _handle_search_all uses its own
  rerank apply that bumps a counter on every path. _handle_search
  was the only early-return gap.
• D3: _handle_tell_me_about is the only handler that
  auto-fetches a single article based on the extracted topic.
  Other intents take the topic literally; synthesize uses RAG-style
  passage retrieval where decomposition would lose the attribute
  context (pre-existing design out of scope).
• D4: _format_search_text has three call sites — only the
  compact filtered one needed filter_text.
  search_with_filters_with_canonical_splice (non-compact filtered)
  already uses _format_filtered_response which natively emits
  the qualifier.

Cross-feature composition verified

• search for Photosythesis's reproduction in namespace C if you would → universal trailing strip peels if you would → intent
  = filtered_search → _maybe_rerank_compact bumps counter →
  _format_search_text renders with filter_text. D1+D2+D4
  compose.
• tell me about Photosythesis's reproduction if you would →
  universal strip peels if you would → intent = tell_me_about
  → D3 retry fires on possessive topic → photosynthesis. D1+D3
  compose.

Tests

• 40 new tests in tests/test_post_b2_beta_fixes.py across 10
  classes (TestD1TrailingModalPoliteness,
  TestD1ParseIntentEndToEnd, TestD1SiblingUniversalTrailingModal,
  TestD1RegexSync, TestD1Pass3ChainedIntentPolitenessLeak,
  TestD2RerankerCounterOnNoResults,
  TestD3PossessiveDecompositionRetry,
  TestD4FilteredSearchEchoQualifier, TestRegressionGuards).
• Full suite: 2360 passing, 54 skipped, 38 deselected. mypy
  clean across 52 source files. black + flake8 clean. CI checks
  all green (CodeQL, SonarCloud, bandit, security scanning,
  6 OS × Python matrix, both [reranker]-extra suites,
  performance benchmarks).

Methodology evolution

• "Narrow-scope sibling" pattern — now 8 sweeps strong. Both
  pass-2 and pass-3 surfaced a single sibling of pass-1's D1
  fix-family: pass-2 caught the universal-layer mirror (modal
  class missing from _TRAILING_POLITENESS_RE); pass-3 caught the
  upstream-chained-guidance mirror (trailing-politeness strip
  missing from _chained_intent_guidance). Both are STRUCTURAL
  mirrors of fixes already shipped — pass-2's sibling mirrors the
  post-a20 PD2-1 universal-strip extension, pass-3's sibling
  mirrors the post-a24 P1-D6 param-leak strip placement.
• "Fix unlocks new paths" — 9th consecutive sweep. D3 is
  particularly nasty because the failure mode changed from
  explicit No search results found (pre-b1 P1-D5) to silent
  wrong answer (post-b1 P1-D5 affix retry → post-b2 D3 retry).
• New invariants pinned via canonical-source tests — two
  feature-level guards: (a) leading + trailing politeness regexes
  must share the modal class; (b) the no-results early-return path
  in _handle_search must route through _maybe_rerank_compact.
  These pin the "added X to one side, forgot the other side"
  drift class that drove both pass-2 and pass-3 defects.