Resolve upstream merge conflicts from t3-code/main fork

[harrryyd]

What to build

Resolve all 23 unresolved <<<<<<< HEAD / >>>>>>> t3-code/main merge conflict markers across 16 files. These originated from the initial fork of t3-code/main and block all subsequent modularization work. Resolve in favor of the fork's additions where the fork diverged from upstream; resolve in favor of upstream where the fork has not modified the affected code.

Affected files

• AGENTS.md
• packages/shared/package.json
• packages/contracts/src/rpc.ts
• packages/contracts/src/ipc.ts
• packages/client-runtime/src/wsRpcClient.ts
• apps/web/src/localApi.test.ts
• apps/web/src/environmentApi.ts
• apps/web/src/components/ChatView.browser.tsx
• apps/web/src/clientPersistenceStorage.ts
• apps/server/src/ws.ts
• apps/server/src/provider/Layers/ProviderRegistry.test.ts
• apps/server/src/provider/Layers/ClaudeAdapter.ts
• apps/server/src/persistence/Migrations.ts
• apps/server/src/orchestration/Layers/ProjectionSnapshotQuery.ts
• apps/server/integration/OrchestrationEngineHarness.integration.ts

Acceptance criteria

• All 23 <<<<<<< / >>>>>>> markers removed from all 16 files
• vp check passes (typecheck + lint)
• vp test passes (full test suite)
• Git working tree shows no conflict markers: rg "<<<<<<<|>>>>>>>|=======" returns empty
• Each resolution follows: fork additions win where fork diverged; upstream wins otherwise

Blocked by

None - can start immediately

[harrryyd]

Implemented and merged to main.