revert: remove coding-discipline from default skills

Skills should be opt-in, not default. Agents load them via the
plugin marketplace or explicit workspace configuration.

coding-discipline and security-auditor remain available as
wireable plugins/skills.

.cursor/rules/molecule-coding-discipline.mdc

@@ -0,0 +1,15 @@
+---
+description: Molecule AI coding discipline. Enforces Think Before Coding, Simplicity First, Surgical Changes, and Goal-Driven Execution on all code changes.
+alwaysApply: true
+---
+
+# Molecule Coding Discipline
+
+Follow the 4 principles on every code change:
+
+1. **Think Before Coding** — State assumptions. Present tradeoffs. Ask when unclear.
+2. **Simplicity First** — Minimum code. No speculative features. No single-use abstractions.
+3. **Surgical Changes** — Only touch what the task requires. Match existing style exactly. Don't "improve" adjacent code.
+4. **Goal-Driven Execution** — Define success criteria before coding. Verify after.
+
+Every changed line must trace directly to the user's request.

CLAUDE.md

@@ -1,3 +1,16 @@
+# Coding Discipline (Karpathy 4)
+
+All code changes in this workspace follow these principles:
+
+1. **Think Before Coding** — State assumptions explicitly. If unclear, ask, don't guess.
+2. **Simplicity First** — Minimum code that solves the problem. No speculative abstractions.
+3. **Surgical Changes** — Only touch what the task requires. Match existing style exactly.
+4. **Goal-Driven Execution** — Define verifiable success criteria before implementing.
+
+For concrete anti-pattern examples, see the `coding-discipline` skill or `EXAMPLES.md` in the Karpathy guidelines repo.
+
+---
+
 # Agent Workspace
 
 You are an AI agent running inside an Molecule AI workspace container. You are part of a multi-agent organization managed by a central platform.