chore: update Go 1.25, add zap logger dependency

fix: resolve compilation errors — FusionEngine type, Config fields, Fuse method

Update config: Cognee defaults to local (no paid cloud key required)

Add hardware detection, cloud mode support, and fusion engine tests

HelixMemory: Complete fusion of Cognee + Mem0 + Letta memory systems

chore(docs): add documentation and challenge scripts

docs: add comprehensive ARCHITECTURE.md for HelixMemory module

feat(infra,security): add infrastructure bridge, security tests, Makefile

feat: add challenge scripts and enterprise website

feat(tests,docs): add integration/e2e/stress/benchmark tests and documentation

test: add comprehensive unit tests for all HelixMemory packages

feat: implement all 12 power features for HelixMemory

feat: initialize HelixMemory unified cognitive memory engine