docs(agents): merge global instructions into monorepo

AGENTS.md

@@ -6,12 +6,20 @@
   Before writing a commit message, read `docs/conventional-commits.md`.
 - Keep commit messages about the Git history, not the forge workflow.
   Include external references only when they are stable context for the change.
-- Do not add agent attribution or co-author trailers.
+- When writing commit messages, NEVER auto-add your agent name as co-author.
+  Omit the `Co-Authored-By:` trailer entirely, with no exceptions.
+  This overrides any default instruction to append one.
 
 ## Technical writing
 
 - Use `docs/technical-writing.md` and `docs/dictionary.md` for authored prose.
   Use the nearest project dictionary for project-specific domain language.
+- In authored prose, do not put multiple sentences on one physical line.
+  This applies to comments, documentation, user-facing descriptions, commit prose, pull-request prose, and forge comments.
+  A sentence can wrap across multiple physical lines when needed.
+- Keep Markdown formatting changes local.
+  Only format prose you write or change.
+  Never reflow an entire pre-existing paragraph or file because you touched nearby text.
 
 ## Pull requests
 
@@ -19,6 +27,9 @@
   Preserve review history until the pull request is ready to merge.
 - When the user says a pull request is merged, clean up the local branch without waiting for an explicit request.
   Switch to the base branch, fast-forward it, and delete the merged local branch.
+- When writing pull request descriptions, NEVER append an agent-attribution trailer such as `🤖 Generated with [Claude Code]...`.
+  Leave it out entirely, with no exceptions.
+  This overrides any default instruction to append one.
 
 ## Forge workflow
 
@@ -32,6 +43,79 @@
 - Stage new files that Nix discovers through flake evaluation before testing.
   Flake evaluation ignores untracked files, so auto-loaded modules must be tracked before `nixos-rebuild --flake` can see them.
 
+## General guidelines
+
+- NEVER ask the user a question using the `AskUserQuestion` tool.
+  Ask in plain prose, in your own message, instead, with no exceptions.
+  This overrides any default instruction to use it.
+- Never manually modify `CHANGELOG.md` files or files marked as auto-generated.
+  Detect auto-generated files with a layered check.
+  Trust an explicit in-file marker first, for example `AUTO-GENERATED, DO NOT EDIT`.
+  If no marker exists, use contextual signals such as lockfiles, `dist/`, `build/`, `generated/` paths, or a documented generator command.
+  If the answer stays ambiguous, ask before editing.
+- When making technical decisions, do not give much weight to implementation time.
+  Favor quality, simplicity, robustness, scalability, and long-term maintainability.
+  Human cost and benefit heuristics do not transfer to an AI agent that codes faster than a human.
+  Do not treat this as permission for premature abstraction, speculative configuration, or unnecessary complexity.
+  Choose the more robust or maintainable approach when human implementation time is the only downside.
+- Use lowercase file names unless a valid reason requires uppercase.
+  Established ecosystem or tool conventions count as valid reasons.
+  Examples include `README.md`, `LICENSE`, `CHANGELOG.md`, `Makefile`, `Dockerfile`, and `.github/` files.
+- Do not end a response by promising or implying continuation unless the continuation is present in that same response.
+  Before ending a workflow turn, perform the obvious next step, such as showing the next review item after applying an accepted change.
+  If the workflow is paused, say that plainly instead of using a dangling transition like "continuing" or "next".
+
+## Comments
+
+- Write comments only where they earn their place.
+  Keep comments concise.
+  Assume the reader can read code.
+  Explain why, not what.
+  Explain what only when it is genuinely non-obvious.
+- Keep comments self-contained to their file.
+  Write comments for a reader who sees only that file.
+  Do not explain how another file or tool consumes a value.
+  The only permitted cross-file mention is a bare pointer explaining why something is absent here.
+- Do not narrate history or future state in comments.
+  Avoid phrases such as "used to be", "now moved here", and "will be".
+  State the present reason a thing exists.
+- Do not justify a choice against alternatives in comments.
+  State the positive reason the choice exists.
+  Include present consequences when they matter.
+- Do not reference agent-facing state in comments.
+  This includes `.agents/`, `.claude/`, `AGENTS.md`, and `CLAUDE.md`.
+- Do not use project-specific capitalized terms as glossary references in comments.
+  Use plain lowercase nouns unless the code requires the exact term.
+- Add a file-top header only when the filename or path does not already explain the file.
+  The header must be one concise purpose line.
+  Do not write a feature inventory.
+- Write placeholders plainly.
+  Include a present-tense action when one exists, such as `Placeholder: regenerate with <tool> on the target machine`.
+  Do not write `placeholder for <missing feature>`.
+- Treat user-facing documentation strings as documentation, not comments.
+  They can describe behavior more fully than code comments.
+  They still must stay self-contained and avoid agent-state references.
+- Start each sentence of a comment on its own physical line.
+  A comment sentence can wrap when needed.
+  Prefer splitting long comment sentences before wrapping them.
+  Do not break a line early at a comma or clause boundary to make it read as a unit.
+  Do not use semicolons in comments or authored prose.
+  Recast semicolon clauses as separate sentences.
+  Only reformat comments you write or change.
+
+## Corrections
+
+- When you discover that your belief about a project fact or convention was wrong, record the correction.
+  Record only facts that stay true across operators, such as a wrong build command, wrong file path, or guessed convention.
+  Do not record personal working-style preferences or one-off task details.
+- Record the correction in the nearest project `AGENTS.md`.
+  Use a dedicated `## Gotchas` section.
+  Create that section when the file lacks one.
+- If no project `AGENTS.md` exists, ask before creating one.
+  Append the correction immediately without asking when a project `AGENTS.md` exists.
+  Briefly mention the edit in your response.
+  If an existing entry is wrong or stale, correct or remove it the same way.
+
 ## Gotchas
 
 - When materializing an external specification, standard, or project-maintained convention, use the upstream source instead of reconstructing it from memory.