chore(release): bump to 2.1.0

[stonematt]

Summary

• Bumps to 2.1.0 across package.json, package-lock.json, and server.json — the first real use of the npm version automation from Automate version bumps across all three manifests #95
• Adds the 2.1.0 CHANGELOG entry covering manifest parser over-collects English words as verbs under Discover #53, Release v2.0.4 #89, Sync server.json version to package.json and fail the build on drift #91, Add root AGENTS.md naming the install path #92, CI: test.yml never runs on dev, so no feature PR is tested before merge #94, and Automate version bumps across all three manifests #95

Minor rather than patch: AGENTS.md is new, and the verb-parser fix changes which verbs obsidian_help reports. Nothing breaking.

No Closes lines — release PR #99 already carries them for the staged issues.

Test plan

• npm version minor --no-git-tag-version synced all four version fields in one command
• npm test — 211 tests, 210 pass, 0 fail, 1 pre-existing skip
• CI matrix green