dx: extract hardcoded known-preset list in config.ts into a shared constant

[George-iam]

In src/storage/config.ts, the parseConfig function contains a hardcoded array of known preset IDs used for validation warnings: ["essential-safety", "ai-agent-guardrails", "production-ready", "team-collaboration"]. This duplicates the preset IDs already defined in src/presets.ts via the PRESET_BUNDLES array. If a new preset is added to presets.ts, the config warning list will silently become stale. Extract the known preset IDs from PRESET_BUNDLES and use that as the single source of truth in both places.

Relevant files:

• src/storage/config.ts — replace the hardcoded known array (line ~66) with a reference to the shared constant
• src/presets.ts — export a PRESET_IDS constant (e.g., PRESET_BUNDLES.map(b => b.id)) or export PRESET_BUNDLES (already exported) and derive IDs in config.ts

Acceptance criteria:

• The hardcoded preset ID list in config.ts is replaced with a derived list from presets.ts
• npm run lint and npm test pass
• No change in runtime behavior (same warning message for unknown presets)