[pavelhov]

Opus 5.5 context compaction now uses a bounded maintenance budget instead of inheriting maximum-effort implementation settings. Two post-0.1.23 compactions reached exactly 40,192 output tokens and stopped with max_output_tokens; the adapter had treated a heuristic thinking allowance as though it reserved space for summary text, while adaptive thinking shares the entire output limit.

For fresh compactions on the verified Opus 5.5 model at Anthropic's canonical API, effective effort is at most medium and an omitted output limit becomes 64,000 tokens. The budget policy preserves explicit limits and lower efforts, and leaves ordinary work, other models, and custom destinations unchanged. Both compact endpoints reject partial summaries without installing them or automatically retrying. The older endpoint now streams routed Anthropic generation internally, retaining its client JSON contract while allowing long summaries to receive pings beyond the connection-header deadline. This is bounded headroom, not a guarantee that every history can be summarized within the limit; Anthropic documents adaptive thinking and the model's 128K maximum.

Regression validation first reproduced the old 40192/max wire policy with 20 failing cases, then passed all 120 focused tests through the real adapter and both endpoints. Typecheck, privacy scan, GUI lint/i18n/tests/build, documentation build, and macOS core/UI checks passed. The GUI runner recovered one existing timing-test file with its automatic focused retry. The first full backend run passed all 633 files after a focused appcast-test retry. Independent Opus review identified the v1 timeout risk; its follow-up confirmed the streaming fix with 117 passing focused tests and no remaining findings. The final backend run isolated one older integration fixture that still returned non-streaming JSON; updating that fake to honor stream: true preserved every client-history assertion, and rerunning only tests/server-auth.test.ts passed all 70 tests. The remaining 632 files passed in the full run. Required CI then passed the complete final commit, including the full suite, in 5m42s.

Release security review: the existing external Ed25519 key pair and installed trust anchor match, and Sparkle tool hashes match the pinned 2.9.6 release. The patch changes no credential handling, destinations, release scripts, signing policy, or updater trust. Version 0.1.24 will use immutable archives and the existing authenticated feed, with isolated installed-app qualification plus downloaded-draft and public-byte verification before completion. The universal macOS app remains an ad-hoc signed, unnotarized preview.