feat(semantic): Semantic Intent Mode (Phase A MVP)

[MeRezaRezaei]

Summary

Per-directory semantic chat mode: the main chat sees only sanitized IntentEnvelope answers while operator sub-agents run real tools via the existing DelegationBroker.

• Envelope protocol: IntentEnvelope / Op / AcceptState types (Rust + TS mirrors), serde round-trip tested
• Aggregation: parallel op envelopes grouped by intent, ops/results/raw merged
• Broker integration: run_semantic_core drives operator + summarizer sub-agents; raw tool output never surfaces as result (enforced by test); failure → denied envelope
• Storage/API: FolderKind::Semantic (string-backed, no migration), POST /semantic_submit (body { req: SemanticRequest })
• Frontend: SemanticComposer + SemanticResultView (raw hidden behind off-by-default toggle), message-input.tsx branches on folderKind === "semantic"

Test plan

• cargo clippy --all-targets --features test-utils -- -D warnings
• cargo test --features test-utils semantic — 11 tests pass
• pnpm eslint .
• pnpm test — 4917 passed
• Manual smoke: seed a semantic folder, submit intent via composer, verify sanitized result view

Notes

Phase A is human-in-the-loop (reuses DelegationBroker; no new LLM loop). Phase B (autonomous supervisor) is intentionally deferred. Composer branch is inert until upstream wiring passes folderKind="semantic" (folder-creation UI deferred).