v0.1.27 release: Complete implementation

Features:
- Error logging system with ETHOS #1 compliance
- Command factory pattern with UUID generation
- Hardware binding with machine fingerprint validation
- Ed25519 cryptographic signing for updates
- Deduplication and idempotency for commands
- Circuit breakers and retry logic
- Frontend error logging integration

Bug Fixes:
- Version display using compile-time injection
- Migration 017 CONCURRENTLY issue resolved
- Docker build context fixes
- Rate limiting implementation verified

Documentation:
- README updated to reflect actual implementation
- v0.1.27 inventory analysis added

aggregator-server/internal/database/migrations/017_add_machine_id.up.sql

@@ -6,7 +6,8 @@
 DROP INDEX IF EXISTS idx_agents_machine_id;
 
 -- Create unique index to prevent duplicate machine IDs (allows multiple NULLs)
-CREATE UNIQUE INDEX CONCURRENTLY idx_agents_machine_id_unique ON agents(machine_id) WHERE machine_id IS NOT NULL;
+-- Note: CONCURRENTLY removed to allow transaction-based migration
+CREATE UNIQUE INDEX idx_agents_machine_id_unique ON agents(machine_id) WHERE machine_id IS NOT NULL;
 
 -- Add comment for documentation
 COMMENT ON COLUMN agents.machine_id IS 'SHA-256 hash of hardware fingerprint (prevents agent impersonation via config copying)';