Add an adaptive prompt section describing the available context and what each template contains

[ad4mou]

Summary

• The agent now gets a short guide to the project context in its system prompt: what each folder is for, and what each per-table file contains and when to read it. Before, it was only told the files existed, so it often read the wrong one or none.
• The guide only mentions what the project actually has. The per-table file list comes from nao_config.yaml, and folders like semantics/ or docs/ appear only when they exist and have something in them so the agent never goes looking for something that isn't there.
• annotations.md is now called out as the place for human notes, and the agent is told to trust it over the generated files when they disagree.
• Removed leftover mentions of description.md and how_to_use.md in the recommendations prompt and the two context skills. Those files were deleted a while back and no longer exist.
• The checks run once per user message.

Closes #980

Two decisions regarding the issue

• Per project, not per table. The issue asked for the file list to adapt to each table. The config already decides which files sync writes, and checking every table folder would mean scanning thousands of directories for the same answer. So the list adapts per project instead.
• No regeneration on context push. : The genuinely useful version where the prompt adapts to the user's DB ("read annotations.md first for what a column means", "check crm.md before sales questions") needs a model to read the files and understand them which is already what the write-context-rules skill already does, with a human reviewing the result. Doing it automatically on every sync would pay for that pass every time and ship it unreviewed.

[github-actions]

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[cubic-dev-ai]

All reported issues were addressed across 10 files

<sub>Reply with feedback, questions, or to request a fix.

Re-trigger cubic</sub>

[cubic-dev-ai]

All reported issues were addressed across 15 files (changes from recent commits).

<sub>Reply with feedback, questions, or to request a fix.

Re-trigger cubic</sub>

[ad4mou]

this feels stale but it's actually because we still accept desription in nao_config without labelling it a bad config so that users upgrading from older versions don't get their sync refused. So we need to filter it out here since our new prompt doesn't support description

[ad4mou]

LGTM