Release v0.3.0

Native Google Sheets and Google Docs support (closes #28).

New tools (8):
  Sheets — read_range, write_range, create, list_tabs
  Docs   — read, insert_text, replace_text, create

OAuth scopes added:
  https://www.googleapis.com/auth/spreadsheets
  https://www.googleapis.com/auth/documents

IMPORTANT: existing users must run /gws:reauth to pick up the new
scopes. Before approving the browser consent screen, review what the
new scopes grant — full read and write access to every spreadsheet
and document in the account's Google Drive. The /gws:reauth skill
carries the pre-consent language for v0.2.x → v0.3.0 upgrades.

Also in this release:
- Consistent scope-error UX across all services. Insufficient-scope
  403s now surface a clean, agent-actionable reauth prompt via
  auth.ScopeError instead of raw Google wording.
- Proactive scope check on first Sheets/Docs call — stale tokens
  fail fast with the reauth prompt, not mid-write 403.
- Untrusted-content fencing on read tools and irreversible-write
  warnings in write-tool descriptions.
- Dual-content returns (text summary + structured JSON) on Sheets
  and Docs tools so agents don't have to re-parse prose.

Changes since v0.2.4:
- #44 Add native Google Sheets & Docs support (closes #28)
- #45 Bump version to 0.3.0

Release v0.2.4

Ship the OAuth non-blocking fix (#41).

Changes since v0.2.3:
- #41 Split OAuth into non-blocking start + complete (fixes #40)
- #37, #39 Go module updates
- #38 CI action update

Bump version to 0.2.3 (#25)

Include gemini-extension.json and CONTEXT.md in release.

Bump version to 0.2.2 (#21)

Version bump for release: send_draft, UTF-8 fix, HTML support, tool
routing.

Bump version to 0.2.1 (#18)

Version bump for release with auto-download binary fix.

Add reauth tool for refreshing OAuth tokens (#13)

## Summary

- New **`gws.accounts.reauth`** tool — re-runs OAuth for an existing
account to refresh tokens or pick up new scopes, without changing
label/default/credentials
- Validates the re-authorized email matches the original account
- New **`/gws:reauth`** skill with usage guidance
- Exported `CredentialsForAccount` on `ClientFactory` (was unexported)

## Test plan
- [x] `make test` passes
- [x] `make lint` clean
- [ ] Manual: reauth an existing account, verify settings unchanged

Add release workflow, --version flag, and refresh README (#4)

## Summary

- **`.github/workflows/release.yml`** — triggers on `v*` tags,
cross-compiles darwin/arm64, darwin/amd64, linux/amd64, linux/arm64 and
publishes binaries as GitHub Release assets via
`softprops/action-gh-release`
- **`cmd/gws-mcp/main.go`** — adds `version` variable (injected via
`-ldflags` at build time) and `--version` flag
- **`README.md`** — prebuilt binary download as primary install path (no
Go required), Go version updated to 1.25+, credentials section clarified
for multi-account use, removed hard-coded test count, simplified
platform examples

## Test plan

- [x] `make test` passes
- [x] `make lint` clean
- [x] `./bin/gws-mcp --version` prints `dev`
- [ ] After merge: tag `v0.1.0` → release workflow publishes 4 binaries