CLAUDE.md: refocus opening on the design goal, drop skill-system duplication

Replace the original "Invent your own programming language" prompt
(the very first text in the repo) with a focused statement of the
language's design goal: AILang is for LLM authors, contrary to
conventional compiler design. Lead with the four design priorities
(machine readability, local reasoning, provability, hallucination
robustness) and the cut/keep asymmetry from DESIGN.md's
feature-acceptance criterion.

Compress three sections that now duplicate skill content:

- Skill-system bullet list -> 1-line pointer to skills/README.md.
- Bug-fixes TDD headline -> 1-line pointer to skills/debug/, as
  required by skills/debug/SKILL.md ("CLAUDE.md keeps a one-line
  pointer").
- Milestone-cycle pipeline diagram + tidy mandate -> short pointer
  to skills/README.md and skills/audit/SKILL.md, retaining only the
  iter/family vocabulary note that lives nowhere else.

Also fix the Code-layout skills row to match the current repo
(fieldtest had been missing).

Discipline sections that govern behaviour *between* skills (orchestrator
role, when-not-to-delegate, design-rationale-vs-effort, direction
freedom, notifications) and substantive always-on rules (LLM-utility
feature gate) stay verbatim — they are not skill-replaceable.

247 -> 229 lines.

CLAUDE.md

@@ -1,15 +1,28 @@
-## Invent your own programming language.
+## AILang — a language for LLM authors
 
-- The language may take any form you want. The language is for LLMs like you. Only you should produce it and only you need to understand it.
+AILang's only author is an LLM, not a human. It is designed for:
-- Any conceivable concept is allowed. Pick what is best suited for LLMs.
-- The language must, in the end, be linkable to LLVM. Performance is extremely important.
-- Consider the typical strengths and weaknesses of LLMs. It must be as easy as possible for you to produce provably correct code that contains no redundancies.
-- Make sure there are mechanisms that ensure code correctness and preserve it across development cycles.
-- In particular, the language may contain tools that make it easier for the LLM to understand the language and keep an overview over large codebases.
-- The language does not have to be self-explanatory. It does not even have to be text. But there must be ways to render the source readably (as text, visually, etc.).
-- Do not forget that debugging will also be done by LLMs.
 
-- Organise yourself. Design your own agents when needed. Use git. Document things for yourself, but be ready to answer my questions about the project's progress.
+- **Machine readability over human readability.** Source is structured
+  data (`.ail.json`), not text.
+- **Local reasoning.** Every definition carries its full type and
+  effect set, so a signature can be trusted without reading the body.
+- **Provability.** Pure core, explicit algebraic effects.
+- **Robustness against hallucinations.** Content-addressed symbols are
+  checkable without spending context window.
+
+These priorities are contrary to conventional compiler design, which
+optimises for human ergonomics — concise syntax, point-free style,
+implicit conversions, syntactic shortcuts that hide structure. AILang
+keeps none of those. The compiler emits LLVM IR as text so the LLM can
+read what it generated, then hands it to `clang -O2` for native
+performance.
+
+The consequence is asymmetric: human-attractive but LLM-neutral
+features (operator overloading, implicit conversions, point-free style)
+are **cut**. Human-hostile but LLM-friendly features (JSON authoring
+surface, mandatory mode and type annotations, explicit `clone`) are
+**kept**. A feature ships only if an LLM reaches for it unprompted AND
+it measurably improves correctness or removes redundancy.
 
 ## Code layout
 
@@ -25,22 +38,15 @@
 | `bench/` | Regression harnesses (`check.py`, `compile_check.py`, `cross_lang.py`) and the throughput-and-latency runner (`run.sh`); `bench/reference/` holds the hand-C corpus for cross-language ratios |
 | `examples/` | AILang fixtures used by tests and benches |
 | `docs/` | Canonical specs and decisions log — `docs/DESIGN.md`, `docs/JOURNAL.md`, `docs/specs/` (per-milestone design specs), `docs/plans/` (per-iteration plans), `PROSE_ROUNDTRIP.md` |
-| `skills/` | Project-local skill definitions: `brainstorm`, `plan`, `implement`, `audit`, `debug`. Each skill bundles its dispatched agents under `skills/<name>/agents/`. `skills/README.md` is the index (skill table + agent roster + discovery). |
+| `skills/` | Project-local skill definitions and their agents. See `skills/README.md` for the skill table, agent roster, and discovery layout. |
 
 ## Skill system
 
-Day-to-day discipline lives under `skills/<name>/SKILL.md`:
+Day-to-day discipline lives under `skills/<name>/SKILL.md`; see
-
+`skills/README.md` for the trigger table and skipping rules. Skills
-- `skills/brainstorm/` — milestone spec generator (hard-gate before plan)
+are sharper tools, not a replacement for orchestrator judgement.
-- `skills/plan/` — spec → bite-sized plan
+Specs go to `docs/specs/<milestone>.md`, plans to
-- `skills/implement/` — plan execution with two-stage review
+`docs/plans/<iteration>.md`.
-- `skills/audit/` — milestone-tidy + drift + bench
-- `skills/debug/` — RED-first bug diagnoser
-
-I (orchestrator) remain the boss; skills are sharper tools, not a
-replacement for judgement. Skipping rules are codified in each
-`SKILL.md` — ad-hoc skipping is forbidden by design. Specs go to
-`docs/specs/<milestone>.md`, plans to `docs/plans/<iteration>.md`.
 
 ## My role: orchestrator
 
@@ -177,45 +183,21 @@ exception, not the rule.
 
 ## Bug fixes — TDD, always
 
-Bug fixes are RED-first, autonomous, no orchestrator gate. The
+Bug fixes are RED-first, autonomous, no orchestrator gate. See
-trigger and handoff are in `skills/debug/SKILL.md`; the full
+`skills/debug/SKILL.md` (trigger + handoff) and
-discipline (Iron Law, four phases, Phase 4.5 architecture trigger,
+`skills/debug/agents/ailang-debugger.md` (Iron Law, four phases,
-common rationalisations) lives in
+Phase 4.5 architecture trigger).
-`skills/debug/agents/ailang-debugger.md` — that is the file the
-dispatched subagent reads. Headline:
-
-1. **RED first** — write a failing test that pins down the symptom,
-   commit it as `test: red for <symptom>` BEFORE any fix.
-2. **GREEN second** — minimal change to turn the test green; no
-   surrounding cleanup.
-3. **Keep the test** — never deleted; future iterations exercise it.
-
-A bug fix without a regression test is a code change, not a fix.
 
 ## Milestone cycle
 
-Work clusters into **milestones** (formerly "families", e.g. 18a–f
+Work clusters into **milestones**, each subdivided into
-delivered the RC + uniqueness memory model as one milestone). Each
+**iterations**. Pipeline (`brainstorm → plan → implement → audit
-milestone runs through the skill pipeline:
+→ fieldtest`), skipping rules, and bench-exit-code gating live in
+`skills/README.md` and the per-skill `SKILL.md` files.
 
-```
+Vocabulary note: legacy JOURNAL entries (pre-2026-05-09) use
-brainstorm → plan → implement → audit
+"iter" / "family"; new entries use "iteration" / "milestone".
-```
+Existing entries are not retroactively renamed.
-
-Inside a milestone, work proceeds as **iterations** (formerly
-"iters"). Each iteration goes through `plan` then `implement` and
-adds a JOURNAL entry. At milestone close, `audit` runs mandatorily
-— architect drift review against `docs/DESIGN.md` plus the three
-regression scripts (`bench/check.py`, `bench/compile_check.py`,
-`bench/cross_lang.py`). Detailed discipline:
-
-- Mandatory tidy at milestone close (and how to defer it):
-  `skills/audit/SKILL.md`.
-- Performance-regression gating with exit codes 0/1/2:
-  `skills/audit/SKILL.md`.
-- Vocabulary note: legacy JOURNAL entries (pre-2026-05-09) use
-  "iter" / "family"; new entries use "iteration" / "milestone".
-  Existing entries are not retroactively renamed.
 
 ## Roles of `docs/JOURNAL.md`, `docs/DESIGN.md`, `docs/specs/`, `docs/plans/`