[codex] add Crestodian plugin management (#75869)

Summary:
- The branch adds ClawHub plugin search and Crestodian plugin list/search/install/uninstall flows, with docs, changelog, tests, runtime injection, and regenerated config baseline hashes.
- Reproducibility: not applicable. as a bug reproduction request. The high-confidence verification path is cur ... surface search plus exact-head diff/source inspection against the PR's targeted tests and queued CI checks.

ClawSweeper fixups:
- Included follow-up commit: Repair Crestodian plugin management config schema drift

Validation:
- ClawSweeper review passed for head c29cda6005.
- Required merge gates passed before the squash merge.

Prepared head SHA: c29cda6005
Review: https://github.com/openclaw/openclaw/pull/75869#issuecomment-4362360704

Co-authored-by: Peter Steinberger <steipete@gmail.com>
Co-authored-by: clawsweeper <274271284+clawsweeper[bot]@users.noreply.github.com>

docs/tools/plugin.md

@@ -27,6 +27,12 @@ temporary set of OpenClaw-owned plugin packages while that migration finishes.
 
   <Step title="Install a plugin">
     ```bash
+    # Search ClawHub plugins
+    openclaw plugins search "calendar"
+
+    # From ClawHub
+    openclaw plugins install clawhub:openclaw-codex-app-server
+
     # From npm
     openclaw plugins install npm:@acme/openclaw-plugin
 
@@ -433,6 +439,7 @@ openclaw plugins list                       # compact inventory
 openclaw plugins list --enabled            # only enabled plugins
 openclaw plugins list --verbose            # per-plugin detail lines
 openclaw plugins list --json               # machine-readable inventory
+openclaw plugins search <query>            # search ClawHub plugin catalog
 openclaw plugins inspect <id>              # static detail
 openclaw plugins inspect <id> --runtime    # registered hooks/tools/CLI/gateway methods
 openclaw plugins inspect <id> --json       # machine-readable