fix(storage):make init_store return Result

[d4m014]

🗒️ Description / Motivation

First step of migrating Store functions to return Result instead of panicking.
Changes init_store to return Result<Self, Error>, wrapping the return value in Ok(...). All existing .expect() calls inside the function body are left as-is for now, error propagation will come in follow-up PRs.

Related Issues / PRs

• Part of Store swallows DB errors with .expect(), propagate Result through storage layer #306

✅ Verification Checklist

• Ran make fmt — clean
• Ran make lint (clippy with -D warnings) — clean
• Ran cargo test --workspace --release — all passing

[greptile-apps]

Greptile Summary

This is the first step of migrating Store methods to return Result instead of panicking. init_store now returns Result<Self, Error>, with the Self construction wrapped in Ok(...); callers temporarily unwrap with .expect() until full propagation lands in follow-up PRs.

• init_store signature changed from -> Self to -> Result<Self, Error>, with the constructed value wrapped in Ok(Self { ... }).
• from_anchor_state and get_forkchoice_store updated to call .expect() on the Result, preserving existing panic behavior while unlocking future error propagation.

Confidence Score: 4/5

Safe to merge — the change is a minimal signature update with no behavioral difference today.

The only change is wrapping the return value in Ok(...) and adding .expect() at both call sites, preserving existing panic behavior. The sole finding is a stray leading space in one expect message.

No files require special attention.

Important Files Changed

Filename	Overview
crates/storage/src/store.rs	Changes init_store signature from -> Self to -> Result<Self, Error> and wraps the return in Ok(...). Both callers (from_anchor_state, get_forkchoice_store) now unwrap via .expect(). Minor: a stray leading space in the get_forkchoice_store expect message.

Prompt To Fix All With AI

Fix the following 1 code review issue. Work through them one at a time, proposing concise fixes.

---

### Issue 1 of 1
crates/storage/src/store.rs:536
There is a leading space in the panic message — `" store initialization..."` — that differs from the message used in `from_anchor_state`.

```suggestion
                .expect("store initialization should succeed in get_forkchoice_store"),
```

_{Reviews (1): Last reviewed commit: "make init_store return Result" | Re-trigger Greptile}

[MegaRedHand]

LGTM. Left a comment regarding future direction

[MegaRedHand]

Just a heads-up, but we probably need some other crate::error::Error enum for this, which wraps this crate::api::Error.