refactor (connectApp): replace status state machine with storage-as-source-of-truth

[litury]

Closes #117

Problem

AppConnect stored status: pending | approved | rejected | error, used as a state machine between popup and content-script via storage. Side effects:

• Rejection persists — subsequent signer.connect() calls return the cached rejected status without opening a popup (Rejected app connection status is cached permanently, preventing retry #117).
• ExtensionSigner.connect() polled the storage status every 500ms for up to MESSAGING_TIMEOUT (3 min) — fragile and slow to react.
• Storage conflated durable state (is this dApp approved) with transient flow state.

Solution

Treat presence of an AppConnect record as the single source of truth:

• Record exists in appConnects_* → connection is approved.
• Record absent → not connected.

Flow changes:

• Popup Approve writes the AppConnect record directly via AppConnectRepository (storage is cross-context in MV3 extensions).
• Popup Reject simply closes the popup — no storage write.
• ConnectAppHandler in the content-script opens the popup, subscribes to chrome.storage.onChanged, and polls popup.closed. First signal wins: record appears → resolve with WalletInfo; popup closed without a record → reject with App connection was rejected.

Reject cache bug disappears by design: rejection never writes to storage, so the next connect() call starts a fresh flow.

Changes

Removed — state machine artifacts:

• AppConnectStatus enum
• ApproveAppConnectPayload, RejectAppConnectPayload
• ApproveAppConnectHandler, RejectAppConnectHandler (popup writes directly now)
• APPROVE_APP_CONNECT, REJECT_APP_CONNECT from MessagingMethods
• approveAppConnect / rejectAppConnect from PrivateAPIClient

Simplified:

• AppConnect, AppConnectStorageSchema, ConnectAppResponse — no status field
• ExtensionSigner.connect() — single awaited call, no polling loop
• AppConnectRepository.create() — idempotent, overwrites if already approved

Rewritten:

• ConnectAppHandler.handle() — storage-event-driven resolution
• AppConnectState.tsx — reads URL from useSearchParams(), writes record via repository on Approve, just closes on Reject

Added:

• Migration 0010_drop_app_connect_status — strips status field from existing records, removes non-approved entries, bumps SCHEMA_VERSION to 10

Verification

• npm run lint clean
• npm test — 104 tests green, including new storage-event coverage
• npm run build — successful
• Manual testing in Chrome 130+:
  • Vote → Approve → icons appear, wallet connected
  • Vote → Reject or close popup → Vote button returns immediately (no 3-min timeout)
  • Re-Vote after Reject → fresh popup opens
  • Vote on already-connected site → icons appear without popup

Follow-up

During implementation we found that chrome.runtime.onMessage.dispatch — the undocumented method used across PrivateAPIClient / PrivateAPI — does not reliably cross contexts in Chrome 130+. This PR works around it by using storage-based signaling for the connect flow specifically (documented MV3 API). A separate issue will be opened proposing a refactor of the messaging layer to an MV3 service worker pattern.

[litury]

Follow-up: the initial fix in 8ad5faa was too aggressive — it reset terminal status on every connectApp call, including the 500ms polling loop inside ExtensionSigner.connect(). Result: after user clicks Reject in the popup, the next poll would rewrite rejected → pending, the loop kept running until MESSAGING_TIMEOUT (3 minutes), and the dApp spinner hung.

Added 2 commits (5be1470, 0416de3) that gate the reset behind an explicit reset: boolean flag in the payload:

• ExtensionSigner.connect() passes reset: true on the initial call (start of a new connect session)
• Polling calls inside the loop pass no flag (default false) — terminal status flows through unchanged, loop exits normally on rejected / error
• ConnectAppHandler only does the removeById + recreate when payload.reset === true

Verified manually: Reject → spinner returns to Vote button immediately; Approve → proceeds as before.

Happy to squash into a single commit on merge if you prefer — kept them separate so the evolution is visible.

[litury]

Force-pushed with a storage-based approach. Previous commits replaced entirely. See updated PR description.

[litury]

Routed popup approve through PrivateAPI / ApproveAppConnectHandler instead of direct repository access. Also added silent skip for unregistered methods in PrivateAPI listener so popup-only handlers don't conflict with the content-script listener. Added test coverage for the handler.