Feat/ak sync

[shehab299]

No description provided.

[Copilot]

Pull request overview

This PR introduces an stakpak ak sync command to reconcile the local ak knowledge store with the remote Stakpak knowledge store, using per-file SHA-256 content hashes and sizes to plan uploads/downloads and detect conflicts.

Changes:

• Added shared helpers for SHA-256 hex hashing and small human-oriented formatting (size + short hash).
• Extended stakpak_ak::StorageBackend with list_with_meta() and implemented it for local + remote backends.
• Added a new CLI ak sync push|pull workflow (plan/execute/display) with conflict detection and optional resolution strategies.

Reviewed changes

Copilot reviewed 12 out of 13 changed files in this pull request and generated 4 comments.

Show a summary per file

File	Description
libs/shared/src/lib.rs	Exposes new shared format and hash modules.
libs/shared/src/hash.rs	Adds reusable sha256_hex() helper with test vectors.
libs/shared/src/format.rs	Adds format_size() and short_hash() helpers for terminal output.
libs/api/src/stakpak/knowledge/cache.rs	Switches cache ETag hashing to shared sha256_hex() implementation.
libs/ak/src/store.rs	Adds FileMeta + StorageBackend::list_with_meta() for sync reconciliation.
libs/ak/src/lib.rs	Re-exports FileMeta for downstream consumers (CLI sync).
libs/ak/Cargo.toml	Adds stakpak-shared dependency for shared hashing helper.
cli/src/commands/ak/sync/plan.rs	Implements sync planning logic (uploads/downloads/skips/conflicts).
cli/src/commands/ak/sync/mod.rs	Adds ak sync clap surface, orchestration, and tests.
cli/src/commands/ak/sync/execute.rs	Executes a sync plan with per-file fault tolerance and strategies.
cli/src/commands/ak/sync/display.rs	Prints sync plans/reports with size/hash formatting.
cli/src/commands/ak/mod.rs	Wires the new ak sync subcommand into the ak command group.
Cargo.lock	Records new dependency edges (e.g., stakpak-shared used by stakpak-ak).

---

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.