Lifecycle Phase 3: Project Ingestion

[CalebisGross]

Summary

Implement the project ingestion phase — simulates a user running ingest_project on day 2.

Phase 3: Project Ingestion (Day 2)

• Create synthetic project in tmpdir (5 Go files, 2 markdown, 1 config YAML)
• Run ingest engine directly via ingest.Run()
• Run Encoder.EncodeAllPending()
• Assert:
  • Result.FilesWritten >= 5
  • Ingested memories have correct project tag
  • Re-running ingest on same dir produces no duplicates
  • CountMemories() increased by expected amount

Test plan

• ./bin/mnemonic lifecycle-test --phase=ingest passes all assertions
• Dedup verification: second ingest run writes 0 new memories

Part of #248