chore: bump version to 0.2.0

[TerrifiedBug]

Cuts 0.2.0. A minor rather than a patch because this adds two user-facing things since 0.1.9:

• Meeting app exclusions (Add meeting app exclusions and a Settings window #16) — "Ignore " on the meeting prompt and the auto-record toast, backed by meeting_excluded_apps in the config.
• A Settings window (Add meeting app exclusions and a Settings window #16, Lay the Settings window out as a source list #17) — every config key behind a source list, replacing "Edit config…".

The release workflow greps this literal against the tag, so the bump lands before v0.2.0 is pushed.

Pre-flight

Not trusting the tag run to be the first test of the packaging path, per the release runbook:

VERSION=0.2.0 APP_IDENTITY=… SKIP_NOTARIZE=1 ./scripts/build-release.sh   # app + dmg assembled and signed
xcrun notarytool submit dist/yap-0.2.0.dmg --keychain-profile yap-notary --wait
  → {"status":"Accepted","id":"b0fcd827-51cf-40dc-a26b-20a329990600"}

So the real artifact for this version is already known to notarize. Local gate green as well: swift test, release build, the three smoke subcommands, embedded __info_plist, and yap --version reporting 0.2.0.