fix(openclaw): shell safety, HTTP dual-mode, lazy reinit, per-user banks

[slayoffer]

Summary

Comprehensive hardening and feature additions for the OpenClaw Hindsight plugin:

Shell safety

• exec → execFile: Bypass the shell entirely, preventing injection via special characters (quotes, backticks, $()) in chat history. All CLI invocations now use array args.
• escapeShellArg removed: No longer needed — execFile doesn't interpret shell metacharacters.
• sanitize(): Strip null bytes from strings — Node 22 rejects them in execFile() args.

HTTP dual-mode

• Direct HTTP client: When apiUrl is configured, the client talks directly to the Hindsight API via HTTP (fetch), bypassing the subprocess/CLI entirely. Useful for production deployments where the API is already running.
• HindsightClientOptions: Replace 5 positional constructor args with a typed options object for clarity and extensibility (apiUrl, apiToken fields).
• buildClientOptions(): Centralized helper replaces 7 duplicated constructor call sites across index.ts.

Reliability

• Recall timeout: Accept optional timeoutMs parameter for both HTTP and subprocess modes. HTTP defaults to 15s, subprocess to 30s.
• In-flight recall dedup: Concurrent recalls for the same bank reuse one promise instead of firing duplicate requests.
• Timeout/abort handling: Graceful warn-level logging instead of error spam when recall times out (TimeoutError, AbortError).
• Error cause chaining: Wrap errors with { cause } for better debugging stack traces.
• lazyReinit(): Recover from startup health check failure with 30s cooldown and concurrency guard. Only triggers in external API mode.

Per-user memory isolation

• senderId instead of channelId: Derive bank ID from {messageProvider}-{senderId} for proper memory isolation per user, even across channels.
• Dynamic bank ID options: Configurable via dynamicBankId (default: enabled) and bankIdPrefix in plugin config.

Test plan

• npx vitest run — 12/12 tests pass
• Lint passes
• Manual test with OpenClaw + external Hindsight API
• Manual test with OpenClaw + local daemon mode

[nicoloboschi]

the execFile switch is a great improvement for shell safety, but it doesn't fix E2BIG — execFile still calls execve() internally, so ARG_MAX still applies to large content passed as argv. We need to write the content to a temp file and use retain-files for retain(). The index.ts changes (lazy reinit, senderId) look good.

can you rebase?