chore(release): Prepare 0.3.3

[Xuepoo]

Summary

Release prep for v0.3.3, shipping the MCP symbol-tool self-healing work from #28.

Changes

• Cargo.toml / Cargo.lock: workspace + ctx-symbol / ctx-exec version refs bumped 0.3.2 -> 0.3.3; lockfile refreshed via cargo check
• CHANGELOG.md: new [0.3.3] - 2026-08-24 entry (Changed):
  • Symbol lookup errors are self-healing — up to 5 ranked suggestions (prefix > substring > levenshtein<=2, case-insensitive, alphabetical ties) plus an embedded capped mini-outline of top-level symbols in the error message (feat(mcp): Self-healing symbol lookup errors #28)
  • Invalid range-parse errors now state accepted formats (N, N-M, N-) (feat(mcp): Self-healing symbol lookup errors #28)

Gates

• cargo fmt --check ✅
• cargo clippy --all-features -- -D warnings ✅
• cargo test ✅ (285 tests, 13 suites, 0 failures)

No merge/tag — commander handles.