test(e2e): verify persistent work item continuations

[Neonforge98]

Problem

The Work Item continuation stack had unit coverage but no rendered two-instance proof that a non-owner comment runs locally, reuses one durable runner, advances only the shared-plane delta, and becomes visible on the owner instance. The dual-instance harness also let its WebView identifier and Rust service ports disagree, producing false Git-scope failures.

Solution

• align TypeScript and Rust runtime-identity parsing for uniquely profiled WebDriver instances
• pin secondary IDE/CLI ports to one derived runtime identity and clear per-run WebView storage
• refresh the mounted key cache after E2E account writes
• allow deterministic WDIO grep selection
• add F2: Neonforge/VantaNode provision a scoped team and Work Item; VantaNode sends two rendered Discussion comments; both durable runs reuse one hidden runner, the continuation cursor advances monotonically, the second prompt contains only the new plane delta, and Neonforge renders the second turn

Potential risks

The F2 fixture is intentionally large because it drives two real Tauri/WebDriver instances and the official cloud RPC boundary. It runs against the mock provider to avoid spending user credentials, so real External CLI subscription execution remains a separate manual/targeted verification cell. Runtime identity remains bounded to instance ids 2..99; invalid profiled identifiers fail closed to the primary profile.

Verification

• F2 dual-instance WebDriver: 1 passing (1m 31.9s)
• continuation/runtime/dispatch Vitest: 69 passing
• runtime/config Vitest: 29 passing
• Rust runtime_instance tests: 5 passing
• pnpm typecheck
• ESLint / Prettier / rustfmt / git diff --check
• normal pre-commit hooks including Cargo clippy

[Neonforge98]

Superseded by the final two-PR design: #844 removes the Work Item-specific remote continuation bridge, and stacked #939 keeps the reusable audience routing plus sender-local provider-native continuation. This dispatcher/store/handoff stack is intentionally retired.