refactor(skills): group style skills

.pi/skills/nix-style

@@ -1 +1 @@
-../../src/skills/nix-style
+../../src/skills/style/nix

.pi/skills/rust-style

@@ -1 +1 @@
-../../src/skills/rust-style
+../../src/skills/style/rust

src/skills/README.md

@@ -6,6 +6,7 @@ This directory contains monorepo-owned agent skill sources.
 
 ```text
 src/skills/                     Monorepo-owned skill sources
+src/skills/<group>/<skill>/      Grouped monorepo skill sources
 .pi/skills/                     Monorepo-wide enabled Pi skill symlinks
 src/<project>/skills/           Project-owned skill sources
 src/<project>/.pi/skills/       Project-specific enabled Pi skill symlinks

src/skills/nix-style/SKILL.md

@@ -1,34 +0,0 @@
----
-name: nix-style
-description: Use when creating, editing, or reviewing Nix files in this repository.
----
-
-# nix-style
-
-Use this skill as the source of truth for repository Nix conventions.
-
-## Load rules
-
-Read every Markdown file directly under [`rules/`](rules/) before applying this skill.
-Resolve [`rules/`](rules/) relative to this `SKILL.md`.
-
-Finish when all discovered rule files have been read.
-
-## Apply rules
-
-Apply the loaded rules when editing or reviewing Nix files.
-When loaded rules conflict, follow the most specific rule.
-
-After editing Nix files, run:
-
-```bash
-nix run .#fix
-```
-
-Finish when `nix run .#fix` succeeds and the Nix change follows the loaded rules.
-If the command fails, report the failure.
-
-## Maintain rules
-
-When adding or changing files under [`rules/`](rules/), read [`RULE-FORMAT.md`](RULE-FORMAT.md) first.
-Finish when the changed rule files follow that format.

src/skills/rust-style/RULE-FORMAT.md

@@ -1,17 +0,0 @@
-# Rule format
-
-Use this structure for each rule:
-
-```md
-## Rule title
-
-### Rule
-
-State enforceable instructions.
-
-### Rationale
-
-Explain why the rule exists.
-```
-
-Add `### Examples` only when examples clarify the rule.

src/skills/rust-style/SKILL.md

@@ -1,34 +0,0 @@
----
-name: rust-style
-description: Use when creating, editing, or reviewing Rust files in this repository.
----
-
-# rust-style
-
-Use this skill as the source of truth for repository Rust conventions.
-
-## Load rules
-
-Read every Markdown file directly under [`rules/`](rules/) before applying this skill.
-Resolve [`rules/`](rules/) relative to this `SKILL.md`.
-
-Finish when all discovered rule files have been read.
-
-## Apply rules
-
-Apply the loaded rules when editing or reviewing Rust files.
-When loaded rules conflict, follow the most specific rule.
-
-After editing Rust files, run:
-
-```bash
-nix run .#fix
-```
-
-Finish when `nix run .#fix` succeeds and the Rust change follows the loaded rules.
-If the command fails, report the failure.
-
-## Maintain rules
-
-When adding or changing files under [`rules/`](rules/), read [`RULE-FORMAT.md`](RULE-FORMAT.md) first.
-Finish when the changed rule files follow that format.

src/skills/style/STYLE.md

@@ -0,0 +1,29 @@
+# Style skill instructions
+
+Use this document for skills that own repository style conventions.
+
+## Load rules
+
+Read every Markdown file directly under `rules/` before applying the skill.
+Resolve `rules/` relative to the skill's `SKILL.md`.
+
+Finish when all discovered rule files have been read.
+
+## Apply rules
+
+Apply the loaded rules when editing or reviewing files covered by the skill.
+When loaded rules conflict, follow the most specific rule.
+
+After editing files covered by the skill, run:
+
+```bash
+nix run .#fix
+```
+
+Finish when `nix run .#fix` succeeds and the change follows the loaded rules.
+If the command fails, report the failure.
+
+## Maintain rules
+
+When adding or changing files under `rules/`, read `src/skills/style/RULE-FORMAT.md` first.
+Finish when the changed rule files follow that format.

src/skills/style/nix/SKILL.md

@@ -0,0 +1,9 @@
+---
+name: nix-style
+description: Use when creating, editing, or reviewing Nix files in this repository.
+---
+
+# nix-style
+
+Use this skill as the source of truth for repository Nix conventions.
+Follow the shared style skill instructions in `src/skills/style/STYLE.md`.

src/skills/style/rust/SKILL.md

@@ -0,0 +1,9 @@
+---
+name: rust-style
+description: Use when creating, editing, or reviewing Rust files in this repository.
+---
+
+# rust-style
+
+Use this skill as the source of truth for repository Rust conventions.
+Follow the shared style skill instructions in `src/skills/style/STYLE.md`.