feat(csc): add command key extraction and caching logic

[ofekshenawa]

Note

Low Risk
Additive, currently-unused helper logic plus unit tests; main risk is future caching correctness if key extraction misses edge-case command argument layouts.

Overview
Adds initial client-side caching (CSC) command utilities: an allow-list of cacheable read-only commands, isCacheable gating on both allow-list membership and presence of keys, and buildCacheKey which generates length-prefixed cache keys to avoid argument-collision issues.

Also introduces extractRedisKeys to derive the Redis key(s) affected by supported commands (including multi-key, numkeys-style, JSON.MGET, and XREAD layouts), plus comprehensive unit tests covering cacheability decisions, cache-key determinism/collision safety, and key extraction edge cases.

^{Reviewed by Cursor Bugbot for commit 50fa024. Bugbot is set up for automated code reviews on this repo. Configure here.}

[jit-ci]

🛡️ Jit Security Scan Results

✅ No security findings were detected in this PR

---

^{Security scan by Jit}

[cursor]

Cursor Bugbot has reviewed your changes and found 1 potential issue.

^{❌ Bugbot Autofix is OFF. To automatically fix reported issues with cloud agents, have a team admin enable autofix in the Cursor dashboard.}

^{Reviewed by Cursor Bugbot for commit 62bfb07. Configure here.}