v1.1: harden context window and narrator protocol boundary

WP-A1 and WP-A2, implemented in sequence, plus the corrective work the owner
asked for at review. Reported in
planning/reports/v1.1/V1.1-WP-A1-A2-REPORT.md (corrective addendum §R).
Planning package v4.2.

WP-A1: context-window safety reserve
- The prompt leaves max(256, ceil(5% of the effective window)) tokens free
  beside the reply. That is 256 at 4,096 and 820 at 16,384. The value is fixed,
  not a setting, and not calibrated per model.
- M6's 64-token margin is gone. Separators and the chat hint are priced
  exactly; tokenizer drift is the reserve's job.
- Protected context that cannot fit raises ContextOverflow before the model
  is called.
- Streams set stream_options.include_usage. Measured on Ollama 0.33, a stream
  sent no usage without it.
- Each sent turn records fits, exceeded, truncation_suspected or unknown.
  The status is returned on the done event, logged when bad, and shown in the
  context inspector. The turn is always kept.
- Accounting is per-attempt data (attempts.ATTEMPT_KEYS).
- Corrective: a cold model is loaded before its turn is built. When the
  window is unverified but the server answered, contextwindow.ensure_window
  makes one bounded POST /api/generate naming only the model. It sends no
  prompt, generates nothing and writes nothing. It then probes again, and the
  turn is built to that answer. If the load fails, or the window is still
  unknown, the turn falls back to the old behaviour.
- Real host, 4,096 window:
  - v1 cold turn: sent 13,875, the server read 2,050.
  - Same turn after the correction: the window was verified, 3,082 sent,
    3,097 read, fits, 499 tokens left beside the reply.
  - Verified turns elsewhere left 275-2,297 tokens against v1's 23-42.

WP-A2: protocol echo and genre-neutral state prompting
- The vocabulary is shown as the JSON object the model sends, not as
  name(field, ...). This costs 121 tokens.
- The example uses character-1, item-1 and location-1.
- The extractor removes shapes anchored to application-owned text:
  - a vocabulary call line;
  - an echoed length hint;
  - the renderer's scene line left last;
  - an empty fence opener.
- Corrective R5: the echoed continue hint is recognised by its own sentence
  ("Output only story text"). A Hard-limit-opened bracket is removed only
  directly above an echo already cut from the same reply.
- Replay of all 518 real v1 replies: 9 changed, 0 flagged, and no story prose
  removed. That is unchanged by R5.
- Replay of 64 v1.1 replies: 3 changed, 0 flagged. The depth-16 instruction
  tail is removed.
- Identity diagnostic after the correction:
  - 0 identity signals;
  - 0 prompt example identifiers proposed;
  - 0/10 stored turns with protocol or instruction shapes.
- 50-turn run: 51 accepted, 0 of 54 stored turns carry protocol.
- SPECS, render.py and validate.py are identical to v1.0.0.

Compatibility: a real v1.0.0 database reads identically on v1.0.0 and v1.1,
field for field, with schema and user_version 94 unchanged. Undo, redo, Save
Point restore, export and import all work on it. There is no schema,
migration or bundle-format change.

Verification: the backend suite passes 1,534 with 17 skipped and 0 failed.
The frontend passes 165/165, and lint and the build are clean. The offline
container and the browser regression were re-run on this tree (see §R.3).

One test was re-calibrated, not weakened: test_history_block_trim's prefix
test had assumed which turn holds the floor at a 2,048 budget.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01VvegagkhuCZoFPdv4M1egY

DEVELOPMENT.md

@@ -620,6 +620,35 @@ campaign gets less history than the setting asks for, which is a visible,
 explicable loss rather than a silent one, and Settings' **Test connection**
 reports the window it found or says plainly that it could not check.
 
+**It also keeps a margin, and checks the server's own count (v1.1).** The
+application counts tokens with `cl100k_base`, and your model counts them with
+its own tokenizer. The two disagree slightly, so the prompt is built to leave
+`max(256, 5% of the window)` tokens free on top of the reply: 256 at 4,096, and
+820 at 16,384. After each turn the server's reported prompt-token count is
+compared with what was sent. The context inspector shows the result for any
+past turn:
+
+- **The server read the whole prompt:** the ordinary case.
+- **The server did not say how much it read:** the server reported no usage.
+  Nothing is wrong, and nothing is confirmed either.
+- **The server may have cut the start of the prompt:** it read far fewer tokens
+  than were sent. Ollama does this, silently, to a prompt larger than the window
+  the model was loaded with. The turn is kept. Check the window with the
+  commands above.
+- **The prompt was larger than the server allowed for:** its count and the reply
+  together exceed the window. The reply may have been cut short. The turn is
+  kept.
+
+The last two also appear in the server log as a warning.
+
+**A model that is not loaded yet is loaded first.** Before a turn, if the
+application cannot read the window because your model isn't in memory, it asks
+the same Ollama to load it once. That is a `POST /api/generate` naming only the
+model, which generates no text. It then reads the window again, so the first
+turn of a session is built to the window the model really has rather than to
+your setting. If loading fails, or the window still can't be read, the turn goes
+ahead exactly as before, unverified, and the check above still applies.
+
 That does not make the window *bigger*, and the rest of this section is still
 how you do that.