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/023a_command_deduplication.down.sql

@@ -0,0 +1,5 @@
+-- Rollback migration 023a: Command Deduplication Schema
+
+DROP INDEX IF EXISTS idx_agent_pending_subsystem;
+ALTER TABLE agent_commands DROP COLUMN IF EXISTS idempotency_key;
+DROP INDEX IF EXISTS idx_agent_commands_idempotency_key;