release: v3.3.3

Restore-integrity release. Unbreaks fresh `pip install mempalace` from
v3.3.2 by re-tagging current develop, which carries both the plugin.json
consumer (shipped in 3.3.2) and the matching mempalace-mcp entry point
in pyproject.toml (added on develop ~10h after the 3.3.2 tag via #340
by @messelink). #1093 diagnosed by @jphein.

Bumps (all 5 sources agree per Version Guard / CLAUDE.md):
- mempalace/version.py              3.3.2 → 3.3.3
- pyproject.toml                     3.3.2 → 3.3.3
- .claude-plugin/plugin.json         3.3.2 → 3.3.3
- .claude-plugin/marketplace.json    3.3.2 → 3.3.3
- .codex-plugin/plugin.json          3.3.2 → 3.3.3
- CHANGELOG.md                        new [3.3.3] entry

No code changes. The fix for #1093 is already on develop via merged PRs
#340, #1021, #851, #942, #833, #673, #661, #659, #1097, #1051, #1001,
#945.

Branch name intentionally outside the `release/*` ruleset so follow-up
CI-fix commits aren't gated behind a nested PR. (Supersedes #1143 —
closed for exactly that reason after it missed 3 of 5 version files.)

Smoke-tested locally from a fresh develop clone:
  grep mempalace-mcp pyproject.toml .claude-plugin/plugin.json   # both ✓
  python -m build --wheel                                        # ✓
  pip install …-py3-none-any.whl                                 # ✓
  which mempalace-mcp                                            # ✓
  mempalace-mcp --help                                           # ✓

pyproject.toml

@@ -1,6 +1,6 @@
 [project]
 name = "mempalace"
-version = "3.3.2"
+version = "3.3.3"
 description = "Give your AI a memory — mine projects and conversations into a searchable palace. No API key required."
 readme = "README.md"
 requires-python = ">=3.9"