feat(stream): add streaming and session-based compact mode (#4)

[Adityakk9031]

Summary

Fixes #4.

Introduces support for long-running streaming log ingestion (codag wrap --stream / --session <id>) and stateful session management. This enables live continuous log tailing (e.g., kubectl logs -f, docker logs -f, aws logs tail --follow) without killing the child process after the standard 90-second timeout, while exposing session snapshot capabilities over MCP for AI agents.

Key Changes

1. API Layer (internal/api/client.go):
   • Added SessionIngestRequest & SessionSnapshotResponse data structures.
   • Added SessionIngest (POST /v1/sessions/ingest) and SessionSnapshot (GET /v1/sessions/{id}/snapshot) client methods.
2. Session Manager (internal/session):
   • Added manager.go to store and manage active streaming sessions, buffered log lines, and latest compact snapshots.
3. CLI Streaming Flags (cmd/wrap.go):
   • Added --stream flag to bypass the default 90s process timeout cap.
   • Added --session <id> flag to associate continuous log streams with a specific session ID.
4. MCP Tools (internal/mcp/tools.go):
   • Registered snapshot_session tool to allow AI agents to fetch live compacted snapshots for active sessions.
   • Registered list_sessions tool to list active long-running streaming sessions.
5. Tests: Added internal/session/manager_test.go verifying session lifecycle, line buffering, and snapshot retrieval.

Verification

• Tested session creation, line appending, and snapshot generation via unit tests (internal/session/manager_test.go).

[Adityakk9031]

@michaelzixizhou have a look