Prompt Guides

• When editing src/prompts/guides/*.md, run the prompt snapshot tests that consume those guides. For Neon auth guide changes, use npm test -- src/prompts/neon_prompt.test.ts -u and commit the updated src/prompts/__snapshots__/neon_prompt.test.ts.snap; otherwise npm test fails with Snapshot ... mismatched.
• When prompt templates interpolate serialized user-controlled data before replacing reserved markers such as [[AI_RULES]] or [[SERVER_LAYER]], escape those marker strings in the data first. Otherwise a blueprint field or similar value can consume the later placeholder replacement and corrupt both the data and the generated prompt.