[iamnbutler]

Adds CHANGELOG.md and uses it for release notes from now on.

• CHANGELOG.md covers 0.1.0 through 0.10.0, backfilled from the PRs merged between each pair of chore: release commits. Entries are short user-facing bullets under Added, Changed and Fixed, with PR links.
  • The [Unreleased] section covers what's on main now: feat: list recent agent activity in the app's menu #98, feat: paste an image or files into a native text area with desktop_insert, or leave the clipboard replaced on request #99, feat: pause all input from the app menu #100, feat: select the input source through the host #101, chore: run the automatable #42 live checks with npm run live-check #102 and docs: halve the MCP tool list and state the shared rules once #103.
  • Internal-only PRs are left out: fix: update upstream operation inventory tests in each patch that adds an operation #60 and fix: stub missing bounds in the minimized pinned close test (#50) #67 (patch test upkeep) and chore: share result helpers and save_path copy, drop unused exports #105 (refactor, no behavior change).
• scripts/changelog.ts [version] prints one version's section without its heading. It fails when the section is missing or has no bullets.
• The release workflow writes that section to a notes file right after npm run check, so a missing entry stops the run before the 90-minute signed build. It publishes with --notes-file instead of --generate-notes.
• test/changelog.test.mjs fails unless package.json's version has a dated section with entries and a compare link, and an [Unreleased] heading exists. A version bump without a CHANGELOG entry therefore fails npm test. It also tests the section parser.
• docs/build.md gets a short Releases section with the bump steps: version, lockfile, README and mcp.md pins, renaming Unreleased, then gh workflow run release.yml -f publish=true.

The GitHub release bodies for v0.2.0 through v0.10.0 are edited separately with gh release edit. Each gets its section, followed by the existing Full Changelog compare link. All the previous bodies were entirely auto-generated ("What's Changed" PR lists); I checked them line by line before replacing them and kept backups.

npm test (61 tests) and npm run check pass.