docs(projekt-matching): document poison-mail incident and fixes

Design doc: new §4.6 post-mortem (quote char -> guided-decoding
whitespace loop -> dead IMAP conn -> non-terminal mail), updated
module inventory, vLLM/e-mail experience sections, test counts
(51 -> 63) and the latency limitation (now bounded by max_tokens).
User manual: version note + troubleshooting row for repeating alerts.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

docs/projekt-matching-design.md

@@ -5,7 +5,8 @@
 as `72a3b17`. Approved spec:
 `docs/superpowers/specs/2026-07-09-langflow-projekt-matching-design.md`;
 implementation plan (with deviations preamble):
-`docs/superpowers/plans/2026-07-09-langflow-projekt-matching.md`.*
+`docs/superpowers/plans/2026-07-09-langflow-projekt-matching.md`.
+Updated 2026-07-14 after the poison-mail incident (§4.6, commit `36eac66`).*
 
 ---
 
@@ -39,7 +40,7 @@ constraints:
 ### 2.1 The central decision: logic in a package, Langflow as the runtime
 
 All behavior lives in a plain-Python package **`projektmatch`** that is
-unit-tested on the host (51 pytest tests) and copied unchanged into the
+unit-tested on the host (63 pytest tests) and copied unchanged into the
 Langflow container. The seven Langflow custom components are ~30-line
 wrappers that read configuration from Langflow global variables and call one
 package function each. This kept the visual pipeline Langflow promises while
@@ -85,13 +86,13 @@ six visible stages.
 | `rules.py` | Misc rules, half-up match calc, exact description markdown |
 | `mailparse.py` | own-mail detection, project splitting (longest-anchor-title dedup by URL path), canonical URL |
 | `espocrm.py` | CRM client: dedup searches, team lookup (never guessed), ensure-account/contact, unique naming, retries, `X-Status-Reason` surfacing |
-| `llm.py` | vLLM calls (`response_format json_schema`, thinking disabled, no `max_tokens`), German prompts + JSON schemas, retry-on-empty, match completeness retry |
-| `mailer.py` | IMAP (custom keyword, Trash detection, MOVE+fallback), SMTP (STARTTLS, Date/Message-ID) |
-| `stages.py` | Flow-2 stage functions + ctx state machine + CRM verify read-back |
+| `llm.py` | vLLM calls (`response_format json_schema`, thinking disabled, `max_tokens` 8192), German prompts + JSON schemas (requirements capped at 40), retry-on-empty, match completeness retry |
+| `mailer.py` | IMAP (custom keyword, Trash detection, MOVE+fallback, `ensure_alive()` reconnect), SMTP (STARTTLS, Date/Message-ID, Sent copy) |
+| `stages.py` | Flow-2 stage functions + ctx state machine + CRM verify read-back; `page_text()` (project card minus tag cloud, quote sanitization) |
 | `pm_trace.py` | one consolidated Langfuse trace per project via the ingestion API (never raises) |
-| `ingest.py` | Flow-1 orchestration: lock, loop, dispatch, alert aggregation, trash |
+| `ingest.py` | Flow-1 orchestration: lock, loop, dispatch, alert aggregation, trash with flag-checked fallback |
 | `deploy/` | `deploy_files.sh` (rsync + safe restart), `build_flows.py` (variables, API key, programmatic flow construction), `setup_langfuse.py`, systemd units, webhook trigger |
-| `tests/` | 51 unit tests + 5 e2e helper scripts |
+| `tests/` | 63 unit tests + 5 e2e helper scripts |
 
 ### 2.4 Trust boundaries and secrets
 
@@ -146,9 +147,20 @@ the code and worth knowing before touching the system.
 - **Empty completions under load** still occur occasionally (shared GPU,
   concurrent runs): `chat_json` retries empty/unparseable content up to 3×
   with backoff; non-200 fails fast.
-- The old belief "set max_tokens ≥ 1024 for reasoning models" evolved into
-  **"set no max_tokens at all** and disable thinking where you enforce
-  schemas".
+- **A straight `"` in the INPUT text breaks schema-guided decoding** (found
+  2026-07-14, §4.6): the model copies the quote verbatim into a JSON string
+  value, the grammar reads it as end-of-string, the model cannot continue
+  its sentence — and escapes into an **infinite whitespace loop** (whitespace
+  is always grammar-legal) until the token limit, `finish_reason: length`.
+  vLLM's request-level `structured_outputs.disable_any_whitespace` does NOT
+  help: the loop simply moves inside a string literal, where spaces are
+  legal. The robust fix is input-side: `stages.page_text()` maps all quote
+  characters (`„ “ ” " « » ‹ ›`) to `'` before prompting.
+- The old belief "set max_tokens ≥ 1024 for reasoning models" first evolved
+  into "set no max_tokens at all and disable thinking where you enforce
+  schemas" — and then, after the whitespace-loop incident, into
+  **"cap max_tokens at 8192"**: every valid answer fits comfortably, and a
+  degenerate run now burns ~100 s instead of ~10 min before the retry.
 
 ### 4.2 Langflow 1.10 internals
 
@@ -205,6 +217,12 @@ the code and worth knowing before touching the system.
   mail is flagged and skipped (`summary.unreadable`), the connection is
   closed in `finally` — otherwise one poison mail would silently stall the
   pipeline every 5 minutes with no alert.
+- **The IMAP server drops idle connections** during long Flow-2 dispatches
+  (30+ min in the degenerate case, §4.6). `run_ingest` therefore calls
+  `MailBox.ensure_alive()` (NOOP probe + transparent reconnect) before the
+  per-mail finalization, and a failing `move_to_trash` falls back to
+  `flag_checked` (`summary.trashFailed`) so the run continues — the
+  terminal-state rule survives a dead connection.
 
 ### 4.5 Prompt engineering for a 9B model
 
@@ -224,7 +242,41 @@ project (skill result: 86 % Must):
   deterministic layer plus the >85 gate make this tolerable; the annotation
   queue exists to watch it.
 
-### 4.6 Process experiences
+### 4.6 Post-launch incident: the poison-mail loop (2026-07-13/14)
+
+Four days after go-live the pipeline stalled for ~26 hours on one mail,
+sending an identical `[Projekt-Match-Fehler]` alert every ~35 minutes. The
+failure chain — each link necessary, none sufficient alone — is instructive:
+
+1. **Trigger:** one posting (`nproj/3022414`) contained
+   `„ISTQB Certified Tester …"` — a typographic opening quote closed by a
+   straight ASCII `"`. Copied verbatim into a JSON string by the model, the
+   `"` ended the string for the guided-decoding grammar mid-sentence; the
+   model escaped into the whitespace loop (§4.1) and burned the full context
+   on every attempt (~10 min × 3 retries ≈ 35 min per cycle).
+2. **Timeout mismatch:** the ingest dispatch timeout (1800 s) fired before
+   Flow 2 finished, producing a premature `Read timed out` failure.
+3. **Trap:** during the long wait the IMAP connection idled out server-side.
+   The alert still went out (fresh SMTP connection), but `move_to_trash` on
+   the dead connection raised and aborted `run_ingest` **before** the mail
+   reached its terminal state — so the next tick reprocessed the same mail,
+   forever. 66 mails queued up behind it.
+
+Fix (commit `36eac66`, TDD, live-verified): quote sanitization + feeding only
+the project card minus the skill-tag cloud to the LLM (`page_text()`),
+`maxItems: 40` on the requirements schema, `max_tokens: 8192`, and the
+finalization hardening from §4.4. The poison extraction went from 25+
+consecutive failures to a clean 19-requirement result in 21 s; the backlog
+(67 mails) drained in 36 minutes with zero failure alerts and 9 new
+opportunities.
+
+Lessons: **terminal-state guarantees must hold on every path, including
+"connection died mid-run"** — the guarantee is only as strong as its weakest
+finalization step; and **schema-guided decoding turns bad input characters
+into decoding pathologies**, so sanitize model input against the output
+grammar, not just for size.
+
+### 4.7 Process experiences
 
 - **Subagent-driven development with per-task adversarial review** caught
   real defects at every altitude: committed build artifacts, undeclared
@@ -245,7 +297,8 @@ project (skill result: 86 % Must):
 
 ## 5. Verification summary
 
-- **51 unit tests** (pure package, no network); TDD throughout.
+- **63 unit tests** (pure package, no network); TDD throughout (51 at
+  go-live, +1 Sent-copy fix, +11 poison-mail fix).
 - **Component gates:** Flow 2 driven directly via API — consider project
   stable at 86 % across repeated runs with full CRM field verification
   (team, agency linking, contact, description byte-format); reject project
@@ -270,10 +323,12 @@ project (skill result: 86 % Must):
 - Login-walled postings fail with an alert by design (no snippet fallback).
 - Created-but-notification-failed edge case is recorded in the trace, not
   re-sent (spec-accepted).
-- Worst-case in-run LLM latency (nested retries) can exceed the 1800 s
-  dispatch timeout — the ingest side then alerts while Flow 2 may still
-  finish server-side; dedup prevents damage. Cap the budgets if it ever
-  bites.
+- Worst-case in-run LLM latency is bounded since `36eac66`
+  (`max_tokens: 8192` → a fully degenerate extraction costs ~100 s × 3
+  retries ≈ 6 min, comfortably below the 1800 s dispatch timeout). Should
+  the timeout ever fire anyway, the ingest side alerts while Flow 2 may
+  still finish server-side; dedup prevents damage, and the finalization
+  fallback (§4.4) keeps the trigger mail terminal.
 - `parse_run_result` anchors on "any embedded JSON with a `status` key" —
   robust today, but a Langflow upgrade that serializes intermediate ctx
   objects into the run response would need a stricter anchor.

docs/projekt-matching-user-manual.md

@@ -1,7 +1,9 @@
 # Projekt-Matching — User Manual
 
 *The automated pipeline that turns freelancermap project e-mails into evaluated
-EspoCRM opportunities. Version of 2026-07-09 (all acceptance gates passed).*
+EspoCRM opportunities. Version of 2026-07-09 (all acceptance gates passed);
+updated 2026-07-14 (robustness fixes: alert-loop bug resolved, outgoing mails
+now also appear in the Sent folder).*
 
 ---
 
@@ -178,6 +180,7 @@ for the services, `projekt-matching.timer` for the polling). Nothing to do.
 | No mails processed, INBOX grows | `systemctl --user list-timers` — timer active? Langflow healthy (`curl …/health`)? Restart per section 5. Mails are never lost: the next successful tick processes the backlog. |
 | Alert mail: `Abruf fehlgeschlagen` / `Seitentext zu kurz` | freelancermap page unreachable or behind a login wall. Evaluate that project manually via the URL in the alert. |
 | Alert mail: `vLLM HTTP …` / `LLM lieferte kein JSON` / `Read timed out` | the local AI was down or overloaded. Occasional single failures are absorbed by built-in retries; if alerts pile up, check the vLLM service on port 8081. |
+| The **same** alert arrives again and again for the same project | this was a bug (fixed 2026-07-14): one poisonous posting could block the pipeline and repeat its alert every ~35 min. A failed project is now reliably final — if you ever see identical repeating alerts again, restart Langflow (section 5) and report it. |
 | Alert mail: `Team … nicht gefunden` | the CRM user `cowork-api` lost read access to Teams, or a team was renamed. Fix in EspoCRM admin. |
 | A project you expected is missing | check Langfuse: if its trace says `rejected`, the Must-match was ≤ 85 % — the table shows why. If there is no trace at all, check the alert mails. |
 | Duplicate opportunity suspected | duplicates are keyed on the canonical URL (`cProjektlink`). The same project posted by two different agencies has two different URLs and is intentionally kept as two opportunities. |