instructions: the agent speaks the KB language in chat - AGENTS.md § Conversation language, and instructions sync compiles the language tag into every published SKILL.md (#116); 10.0.0-beta.9

Files changed:
- AGENTS.md
- CHANGES.md
- VERSION
- docs/explanation/language-boundaries.md
- docs/reference/commands/types-instructions-and-docs.md
- instructions/CONTRACT.md
- instructions/dev/stack-build/SKILL.md
- instructions/dev/stack-close/SKILL.md
- instructions/dev/stack-dev/SKILL.md
- kb/CONVENTIONS.md
- kb/CONVENTIONS.md.template
- tools/CONTRACT.md
- tools/chemenu/commands/doctor.py
- tools/chemenu/commands/instructions_cmd.py
- tools/chemenu/tests/test_doctor.py
- tools/chemenu/tests/test_instructions_cmd.py

Co-Authored-By: Claude Code <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01SnAJ7Z3CpVD3PRbN73QtU2

AGENTS.md

@@ -13,6 +13,7 @@ maintained permanently; anything mechanical is done by `tools/wikitool`, never b
 
 - [Bootstrap](#bootstrap)
 - [Invariants](#invariants)
+- [Conversation language](#conversation-language)
 - [File naming](#file-naming)
 - [Personalization](#personalization)
 - [Environment](#environment)
@@ -81,6 +82,13 @@ These hold regardless of which skill is active or which part of this file is in
 8. **One rule, one place.** Every normative rule lives at exactly one location; everywhere
    else links to it. Writing a second copy is how the two start disagreeing.
 
+## Conversation language
+
+Write every message to the user - progress notes and the closing report included - in the KB
+language: `language:` in `kb/CONVENTIONS.md`'s frontmatter, read at session start. This holds
+whatever language a file, a tool's output or a source is in; quoted commands, paths and field
+names stay as they are.
+
 ## File naming
 
 What a file is called says who it is for and how it is loaded. This is a rule, not a habit;
@@ -111,9 +119,10 @@ documents. What it may not carry is the same content twice - a README that resta
 contract is a second copy that drifts. `docs verify` enforces the specific case that already
 happened once: no README may hold a copy of the `wikitool` command table.
 
-**Two languages, and which is which.** Which one a line is written in follows from the *For*
+**Two rules for the language of a file.** Which one a line is written in follows from the *For*
 column above - who reads it - and from nothing else: not from who owns the file, and not from
-whether it ever leaves this checkout.
+whether it ever leaves this checkout. What an agent says in the chat is a third matter, and
+has its own section: [Conversation language](#conversation-language).
 
 1. **The control plane is written in English** - this file, `CLAUDE.md`, every `CONTRACT.md`,
    everything under `instructions/`, and the type-specs for non-page artifacts. Quoted
@@ -131,20 +140,20 @@ whether it ever leaves this checkout.
    moves this rule;
    [docs/explanation/language-boundaries.md](docs/explanation/language-boundaries.md) has the
    reasoning.
-2. **An agent speaks the instance's KB language**, whatever this file is written in. The value
-   lives in `kb/CONVENTIONS.md`'s `language:` and nowhere else; an instruction that models a
-   sentence for the user writes it in English like the rest of the control plane, and the agent
-   says it in that language.
-3. **The stack's human documentation is written in English** - `README.md`, `INSTALL.md` and
+
+   An instruction that models a sentence for the user writes that model in English like the rest
+   of the control plane; the agent says it in the KB language ([Conversation
+   language](#conversation-language)).
+2. **The stack's human documentation is written in English** - `README.md`, `INSTALL.md` and
    everything under `docs/` - whatever an instance's `language:` says. It is the
    same text in every instance, and the parts of it that are generated come from English
    sources, so there is no instance whose language it could follow. `CHANGES.md` is a log, not
    documentation, and is not covered.
 
-Nothing checks any of the three mechanically - a stop-word scan would flag the quoted vocabulary
-above and miss a translated paragraph that reads cleanly. They are held up by whoever writes the
+Nothing checks either mechanically - a stop-word scan would flag the quoted vocabulary above
+and miss a translated paragraph that reads cleanly. They are held up by whoever writes the
 text, which is why [instructions/CONTRACT.md](instructions/CONTRACT.md) § "Writing an
-instruction" names the first two at the step where that happens.
+instruction" names the first one at the step where that happens.
 
 **`docs/` carries no normative sentence.** It holds the stack's human documentation - tutorials,
 how-to guides and reference, and under `docs/explanation/` why the stack is built the way it is: