Enhance droid documentation and coding rules:

- Update coder and reviewer descriptions to clarify subagent roles.
- Improve coding rules for modularity and project structure.
- Add new semantic code search skill documentation for ColGREP.
- Introduce rules skill for accessing project coding conventions.

.factory/skills/rules/SKILL.md

@@ -0,0 +1,39 @@
+---
+name: rules
+description: Access and apply project coding rules and conventions from .factory/rules/ directory. Use when needing to follow coding standards, conventions, or guidelines for the project.
+user-invokable: false
+disable-model-invocation: false
+---
+
+# Rules Skill
+
+This skill provides access to project-specific coding rules and conventions stored in `.factory/rules/`.
+
+## Available Rule Files
+
+- **code.md** - General coding conventions and best practices
+- **github.md** - GitHub-specific workflows and conventions
+- **markdown.md** - Markdown formatting rules
+- **project.md** - Project-specific conventions
+- **python.md** - Python-specific coding standards
+- **subagents.md** - Guidelines for using subagents
+
+## When to use this skill
+
+- When starting work on a new task to understand project conventions
+- When unsure about coding standards for a specific language or context
+- When setting up new code that should follow existing patterns
+
+## Usage
+
+The rules are automatically loaded and applied by the system. Individual rule files can be read from `~/.factory/rules/` or `.factory/rules/` in the project directory.
+
+### ColGREP Init
+
+When starting work on a project, run `colgrep init` to build the semantic search index. This enables the colgrep skill for semantic code search across the codebase. The index auto-updates on subsequent searches, so `init` only needs to run once per project.
+
+## Research
+
+- Back all claims with reference code.
+- State only what is proven.
+- If evidence is lacking, say: "I can't find any evidence to support this claim" or "Not enough info".