refactor: inject localStorage via Angular DI in JwtService

[devin-ai-integration]

Summary

Refactors JwtService to receive localStorage through Angular's dependency injection system instead of accessing window.localStorage directly. This makes the service testable without monkey-patching window.

Changes:

• New LOCAL_STORAGE InjectionToken (storage.token.ts): providedIn: 'root' with a factory that returns localStorage. No changes needed in app.config.ts.
• JwtService now inject(LOCAL_STORAGE) and uses proper Storage API methods (getItem/setItem/removeItem) instead of bracket notation.
• jwt.service.spec.ts rewritten to provide a Map-backed mock Storage via { provide: LOCAL_STORAGE, useValue: mockStorage } — no more Object.defineProperty(window, 'localStorage', ...).
• Added zone.js dev dependency — was already imported in test setup but missing from package.json, causing all test suites to fail.
• Pinned @angular/core back to 21.1.1 to match all other @angular/* packages (was accidentally bumped to 21.2.4 by a previous dependabot PR).

Review & Testing Checklist for Human

• Verify getToken() now returns '' (empty string) instead of undefined when no token is stored — all existing callers use truthiness checks so this is backward-compatible, but worth confirming no downstream code relies on undefined specifically
• Run bun run test to confirm all 179 tests pass
• Smoke-test login/logout flow in the browser to verify token persistence works end-to-end

Notes

• The user.service.spec.ts already mocked JwtService entirely via { provide: JwtService, useValue: ... }, so it required no changes.

Link to Devin session: https://app.devin.ai/sessions/6c4b7428c4f54351919bb91211361338
Requested by: @WesternConcrete

---

Devin Review

Status	Commit
⚪ Not started	—

Run Devin Review

💡 Connect your GitHub account to enable automatic code reviews.

---

[devin-ai-integration]

🤖 Devin AI Engineer

I'll be helping with this pull request! Here's what you should know:

✅ I will automatically:

• Address comments on this PR. Add '(aside)' to your comment to have me ignore it.
• Look at CI failures and help fix them

Note: I can only respond to comments from users who have write access to this repository.

⚙️ Control Options:

• Disable automatic comment and CI monitoring