fix: pass claude cli thinking effort (#77410)

Summary:
- Adds a plugin-owned CLI backend argument rewrite hook and wires Anthropic `claude-cli` to translate non-off `/think` levels into Claude Code `--effort`, with docs, changelog, API baseline, and tests.
- Reproducibility: yes. Current main has a high-confidence source reproduction: choose `claude-cli`, set a non ... builds argv from backend args that contain no `--effort` even though `thinkLevel` exists on the run params.

Automerge notes:
- No ClawSweeper repair was needed after automerge opt-in.

Validation:
- ClawSweeper review passed for head be17754009.
- Required merge gates passed before the squash merge.

Prepared head SHA: be17754009
Review: https://github.com/openclaw/openclaw/pull/77410#issuecomment-4372812685

Co-authored-by: stainlu <stainlu@newtype-ai.org>

docs/plugins/sdk-overview.md

@@ -257,6 +257,9 @@ AI CLI backend such as `codex-cli`.
   plugin default before running the CLI.
 - Use `normalizeConfig` when a backend needs compatibility rewrites after merge
   (for example normalizing old flag shapes).
+- Use `resolveExecutionArgs` for request-scoped argv rewrites that belong to
+  the CLI dialect, such as mapping OpenClaw thinking levels to a native effort
+  flag.
 
 ### Exclusive slots