chore: bump version to v0.3.0 (#3509)

Milestone release covering:
- Comprehensive channel matrix test suite (50 tests across 16 platforms)
- Auto-synced README What's New and Contributors across 31 locales
- Anthropic consecutive message merging fix
- Nextcloud Talk Create event support
- Tweet content-hash dedup
- CI/CD stability improvements (Docker timeout, release token, tweet URLs)

Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>

Cargo.lock

@@ -7945,7 +7945,7 @@ dependencies = [
 
 [[package]]
 name = "zeroclawlabs"
-version = "0.2.2"
+version = "0.3.0"
 dependencies = [
  "anyhow",
  "async-imap",

Cargo.toml

@@ -4,7 +4,7 @@ resolver = "2"
 
 [package]
 name = "zeroclawlabs"
-version = "0.2.2"
+version = "0.3.0"
 edition = "2021"
 authors = ["theonlyhennygod"]
 license = "MIT OR Apache-2.0"