Version 2

[Ryun1]

• Milestone lifecycle redesign - 4 independent boolean flags (evidence_provided, withdrawn, paused, archived)
  plus an archive model via superseded_by, replacing the old single-status enum.
• Event-processing rewrite - every on-chain TOM event is now recorded in treasury.events even when chain-trace
  can't attribute it
• Semantics change: "vendor contract" → "project" - the singleton on-chain PSSC (one row, shared by all 42
  projects) is now distinct from the projects (one per fund event). All paths, columns, views, struct names, and
  parser names renamed accordingly.
• Persistent UTxO history - Postgres triggers capture every script-address UTxO into treasury.utxo_history
  synchronously with YACI Store inserts, so chain-trace doesn't fall over once UTxOs are pruned.
• Multi-key vendor datum parser - handles the UTXO-* family's two-party vendor info constructor (KI-VND-01);
  unblocks the milestone-data backfill.
• API consistency pass - paginated envelopes everywhere, ChainTime { unix, iso } for on-chain block times,
  structured error envelopes, ?from_time/?to_time filters on milestones, full-text ?q= search on events.
• New UTxO endpoints (v2.1.0) - GET /api/v1/vendor-contract/utxos returns every currently-unspent UTxO at the
  PSSC labeled per project; GET /api/v1/projects/{id} now inlines current_utxos.
• Statistics + status endpoints rebuilt with structured groupings (database, sync, chain, totals);
  events.by_type now reports real categories.
• Documentation overhaul