docs(devlog): record the Kiro contract landed-state verification

devlog/_plan/260830_kiro_post_answer_tool_calls/020_close_out.md

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+# Close-out — terminal completion contract shipped
+
+Terminal outcome: **DONE**.
+
+## What shipped
+
+PR #3012, merged to `dev` at 2026-08-30T15:31:15Z as `f5a625cf3`. Two injected
+surfaces now state that the private completion tool is terminal:
+
+- `kiroCompletionTool()` schema description in `src/adapters/kiro.ts`, which
+  travels with the tool object the model chooses between.
+- `KIRO_COMPLETION_INSTRUCTIONS` in `src/adapters/kiro-constants.ts`, so the
+  prose contract cannot contradict the schema.
+
+The mid-task rules are untouched: commentary still does not end the turn, and
+the model must still keep using tools before completing. Only what may follow
+the completion call is constrained. `tests/kiro-adapter.test.ts` pins both
+surfaces and asserts the two commentary sentences survive.
+
+## Verification
+
+`bun run typecheck` clean. 197 pass / 0 fail across `kiro-adapter`,
+`kiro-stream`, and `tool-catalog-nudge`. `privacy:scan` passes. The regression
+test was driven red against the old description first.
+
+CI on the merged head: 20 checks green. The single failure, on both
+`test 2/4` and `macos`, was `release version line > the in-tree version is
+never behind a released one` — reproduced identically on a pristine
+`origin/dev` worktree at `df8b3882f` with none of this unit's commits, and
+owned by PR #3006. A release-version bump does not belong in an unrelated bug
+fix.
+
+## Review findings and what was done with them
+
+Three findings, all answered on the PR.
+
+A P1 privacy finding was correct: the measurement table carried a remote
+absolute home path into a public devlog directory, which `privacy:scan` rejects.
+Fixed in `da9b4989c`; the hostname, PID, and version carry the evidence without
+an account identifier.
+
+A truncation-ordering finding was plausible and turned out to be unreachable.
+The completion contract is charged last against
+`MAX_KIRO_INJECTED_INSTRUCTION_CHARS` (16384), so in principle a large enough
+injected context could slice it mid-clause. Measured: the omission notice tops
+out at 922 characters under a hostile 60-tool probe, the nudge ceiling is about
+5540 under the 48-tool and 64-character caps, and the contract is 696 — roughly
+9900 characters of headroom. The caller's system prompt is not charged to this
+budget at all, so no caller input can crowd the contract out.
+
+A reservation guard plus a budget-exhaustion test were implemented first, then
+reverted: the test passed with the guard removed, because the only available
+lever for inflating the budget was the uncharged system prompt. A guard for an
+unreachable path whose test cannot detect its own removal is worse than the
+documented measurement, so the measurement is what stayed. If a future addition
+starts charging caller-sized text to this budget, the numbers above are the
+starting point.
+
+A duplicate-`.find` finding was a false positive: one call rendered across two
+lines. Applying the proposed fix would have deleted the only lookup.
+
+## Follow-up
+
+Causality is not claimed as proven. The pre-change selection rate is recorded at
+25 completion calls across 4069 required-mode attempts; the follow-up is the
+same measurement on traffic served by a proxy running `f5a625cf3` or later.
+Both hosts were on older builds at measurement time (local 2.36.0, `macmini-cf`
+2.35.0), so a restart onto current `dev` is the precondition for that comparison.
+
+## Landed-state verification
+
+Checked against `origin/dev` after both merges (`6f75616f0`), reading the files
+out of the remote ref rather than the working tree:
+
+- `src/adapters/kiro.ts` contains the terminal schema description.
+- `src/adapters/kiro-constants.ts` contains the appended terminal clause.
+- `tests/kiro-adapter.test.ts` contains the both-surfaces regression test.
+- This unit's close-out record is present.
+
+Merge trail: `f5a625cf3` (#3012, the contract change) and `6f75616f0`
+(#3014, this record).