[Ambisphaeric]

Closes #245

What

Two quality defects in the distill/summary output, fixed at the prompt-document + engine layer.

1. Notes read like meeting minutes → human note-taking register

Rewrote the SUMMARY-family template bodies in distill/defaults.ts — the distill window note plus all five hierarchical levels (rolling / episode / five-minute / session / project) — from generic "tight, factual summary of what just happened" into a human note-taking register:

• Lead with the substance ("Feedback to QA — due soon", not "The speaker expressed a goal to provide feedback").
• Explicitly ban transcription-narration framings ("the speaker said/expressed/stated", "the transcript indicates/shows", "it was mentioned/noted/recorded/discussed", "the notes indicate").
• Keep the existing invent-nothing honesty rules.
• Terse: fewest words that carry the fact.

Consistent with the hud-voice surface-language rules. No baked voice dials — the {{tone}}…{{voice.rules}} machinery stays live for user-authored templates. The promptTemplate.distill.json and promptTemplate.summary.json contract examples are updated to the new bodies so their "Mirrors" comments in defaults.ts stay true (byte-verified against the exported defaults).

2. Empty windows still emitted slop → silence over noise

Three complementary drops, all at the distillate (window) seam in distiller.ts:

• Deterministic pre-gate (DISTILL_MIN_CHARS = 12): a window whose observed material (chunk.data, not capture-lane labels — the fields.ts precedent) is below the floor is dropped without an invoke — no distillate, no moments, no entities. Deliberately LOW (lower than the fast-field gates 40/60/80): the distill note is the primary record, so suppressing a real short utterance ("We ship Thursday.") would be data loss. The floor only catches windows too small for any substantive phrase; the sentinel does the "enough words, no substance" judgment.
• Model sentinel (NOTHING_NOTEWORTHY, defined in defaults.ts, imported by the distiller): the distill template instructs the model to reply with exactly this token when nothing is worth noting; the engine drops on an exact, case-sensitive, full-text match of the trimmed response. An embedded occurrence in a real note is kept.
• Empty-response drop: an empty or whitespace-only trimmed response is dropped at the same site — the most literal "nothing", which would otherwise persist as an empty-text distillate.

Downstream verified: the summaries producer already tolerates the resulting gaps. assembleSummaries plans over whatever children exist and buildSummary renders only what it is given, so suppressed windows simply mean fewer/absent children (an all-degraded/empty window degrades honestly rather than fabricating prose).

3. Clobber-safe upgrade

Routed the summary templates through the existing seedOrRefreshBuiltin path and added every rewritten body's prior generation to PREVIOUS_BUILTIN_BODIES. An unedited builtin (version 1 with a byte-identical prior body) auto-upgrades; any user edit (version off 1 and/or divergent body) is never clobbered. PREVIOUS_BUILTIN_BODIES was relocated below the template declarations so its computed keys read initialized consts.

Design notes

• The sentinel + pre-gate + empty-drop live only at the distillate layer (per issue scope). The hierarchical levels are not sentinel-gated: they ride on already-suppressed distillates, so an empty stretch yields no children and degrades honestly rather than emitting a token the producer would have to special-case.
• Known upgrade gap: the conservative version === 1 refresh guard means a pre-fix(distill): factory prompt defaults go neutral — strip the baked voice vector from shipped templates #130 install that already auto-refreshed its distill body once (now version 2) will not auto-upgrade to the notes-voice body. Fresh and still-version-1 installs land it automatically. Documented inline.

Tests

• Template-body assertions: no dial vocabulary, old slop framing dropped, invent-nothing preserved, leads-with-a-note-taking-directive; distill body carries the sentinel and names the banned framings as prohibitions.
• Suppression units (suppression.test.ts): sub-threshold window → no distillate + no invoke; real short utterance clears the floor; exact/whitespace-trimmed sentinel drops; embedded sentinel kept; empty/whitespace-only response dropped; sentinel-with-trailing-period and lowercase variants kept (strictness is deliberate); a sentinel-dropped window followed by a normal window persists the second normally; dropped window produces no moments/entities.
• Upgrade tests: unedited summary builtins auto-upgrade; user-edited summary body preserved; existing distill upgrade/conservative tests updated for the new prior body.

Gate (Node 22, rebased onto origin/main @ 605f780)

• pnpm -r build: clean. pnpm -r test: contracts 114 / fixtures 15 / client 621 / engine 1138, 0 failures.
• Contracts schema regen (pnpm --filter @openinfo/contracts gen): zero drift (beyond the two intentional example edits).
• No contract schema changes.