v0.2.0: Add SSE resume, run export/compare, and crash recovery

[ajit-zer07]

PR Description

Summary

• Resumable SSE streams: The /runs/:id/stream endpoint now supports
  afterSeq / Last-Event-ID for gap-free reconnection. Missed events are
  backfilled from the database in batches, deduplicated against the live hub,
  and each SSE frame carries an id field for browser-native resume. A
  configurable heartbeat (STREAM_SSE_HEARTBEAT_MS, default 15s) keeps
  connections alive through proxies.

• Run insights: New GET /runs/:id/export bundles the full run state
  (run record, session, projection, metrics, artifacts, canonical + raw events)
  into a single JSON payload. New POST /runs/compare diffs two runs on status,
  duration, confidence, participants, and signals.

• Crash recovery: RunRecoveryService runs on application bootstrap,
  queries for active runs (running / binding_session), promotes stalled
  binding_session runs, emits a session.stream.opened recovery event,
  and re-attaches stream consumers from lastEventSeq. Controlled via
  RUN_RECOVERY_ENABLED (default true).

• Progress projection: Adds a progress JSONB column to run_projections
  (migration 0003), wires it through the projection repository and service,
  and bumps PROJECTION_SCHEMA_VERSION to 3. Removes the (row as any) cast.

• Stream consumer reliability: Resets the retry counter after each
  successful event, fixes a timer leak in withIdleTimeout (clears timeout +
  calls iterator.return()), and unrefs timers to avoid blocking graceful
  shutdown.

New files

File	Purpose
drizzle/0003_v2_progress_and_export.sql	Migration: progress column + raw event indexes
src/controllers/run-insights.controller.ts	Export & compare HTTP endpoints
src/insights/run-insights.service.ts	Export bundle assembly, run comparison logic
src/runs/run-recovery.service.ts	Startup recovery of active runs
src/dto/compare-runs.dto.ts	Validation DTO for compare request
src/dto/export-run-query.dto.ts	Validation DTO for export query params
src/dto/stream-run-query.dto.ts	Validation DTO for SSE stream query params

Modified files

File	Change
src/controllers/runs.controller.ts	Rewritten streamRun with resume/backfill/heartbeat
src/runs/stream-consumer.service.ts	Retry reset, timer leak fix, unref
src/storage/event.repository.ts	listCanonicalRange, listRawByRun
src/storage/projection.repository.ts	Persist progress on upsert
src/projection/projection.service.ts	Typed progress read, schema v3
src/db/schema.ts	progress column on runProjections
src/contracts/control-plane.ts	RunExportBundle, RunComparisonResult
src/dto/run-responses.dto.ts	RunBundleExportDto, RunComparisonResultDto
src/config/app-config.service.ts	streamSseHeartbeatMs, runRecoveryEnabled
src/app.module.ts	Register new controller + services
.env.example	New env vars documented
package.json	Version bump to 0.2.0

Test plan

• Run npm test — all 17 suites pass (new specs for recovery, insights, event repo, controllers)
• Verify SSE resume: connect to /runs/:id/stream?afterSeq=5, confirm backfilled events arrive before live ones, no
  duplicates
• Verify heartbeat frames appear at the configured interval
• Test GET /runs/:id/export returns a complete bundle with includeRaw=true
• Test POST /runs/compare with two completed runs, verify participant/signal diffs
• Restart the control plane with active runs in the DB, confirm RunRecoveryService reconnects streams
• Run drizzle:migrate to apply 0003, verify progress column exists
• Confirm graceful shutdown completes without hanging timers