fix: prevent test data from leaking into production DB

[BYK]

Summary

• Add ensureProject() guard that rejects synthetic test paths (/test/...) when LORE_DB_PATH is unset (production DB), preventing test data leaks when test files are run directly with bun run instead of bun test
• Harden bunfig.toml with explicit NODE_ENV=test in [test.env] as belt-and-suspenders
• Expose lore data delete project <path|id> via CLI so leaked test projects can be cleaned up

Context

A test project /test/ltm/debug-forsession leaked into the production DB. Root cause: running a test file directly with bun run (for debugging) bypasses the bunfig.toml preload that sets LORE_DB_PATH to a temp DB. The existing NODE_ENV=test guard in db() doesn't help because NODE_ENV isn't set when the test runner isn't involved.

The new guard in ensureProject() catches this by detecting that paths starting with /test/ are synthetic test paths that should never exist in the production DB. No real project path on any OS starts with /test/.

Changes

File	Change
packages/core/src/db.ts	Guard in ensureProject() — rejects /test/ paths when LORE_DB_PATH unset
bunfig.toml	Add [test.env] with NODE_ENV = "test"
packages/core/bunfig.toml	Add [test.env] with NODE_ENV = "test"
packages/gateway/src/cli/data.ts	Add project type to lore data delete, update help text
packages/core/test/db.test.ts	3 tests for the guard

Testing

• All 1404 tests pass, 0 failures
• Typecheck passes for all 4 packages
• After merging, run lore data delete project /test/ltm/debug-forsession to clean up the leaked project