refactor(skills): inline cross-links, drop Related sections, fix conventions

- all nine files: trailing "Related" sections removed, their unique links
  inlined where the topic actually arises (FFI boundary -> c-cpp, embedded
  frontend -> js-typescript, build scripts -> bash, etc.)
- README conventions: rule 2 mandated a Related Skills section, which now
  contradicts practice — replaced with inline-linking and one-home-per-fact
  rules. The <repo>/<rel path> rule was appended after the wrong section
  last commit; moved into the list where it belongs.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

README.md

@@ -33,10 +33,24 @@ Each language file extends `coding-dev.md` rather than repeating it. A project's
 Skills in this repo follow the same structure as the private counterpart repo, so agents can load either interchangeably:
 
 1. **YAML frontmatter** with `name` (kebab-case, matching the filename) and a `description` starting with *"Use this skill when …"* — the description is what an agent matches against to decide relevance, so it must enumerate concrete triggers.
-2. **Numbered `##` sections**, sequential and unique, ending with a **Related Skills** section that cross-links sibling documents.
-3. **CLI discovery over enumeration** — document the *non-obvious* workflows, gotchas, and constraints. For the routine surface, point at `<tool> --help` rather than transcribing flag lists that will go stale.
-4. **No secrets inline** — reference the environment file that holds them (e.g. `~/.config/environment.d/…`), never the values themselves.
-5. **Verify before documenting** — confirm hostnames, container names, and versions against the live system rather than carrying forward stale claims.
+2. **Numbered `##` sections**, sequential and unique.
+3. **Cross-link inline, at the point the other skill becomes relevant** — never in a trailing
+   "Related Skills" list. A link inside the sentence that raises the topic gets followed; a
+   list at the bottom of a long document does not, and it drifts out of sync with the body.
+4. **One home per fact.** Content that belongs to another skill is *replaced* by a link to it,
+   not duplicated. Where a skill needs its own specific values for something another skill
+   owns the rules for (a container's own template fields, say), keep only the values and link
+   out for the rules.
+5. **Link between skills as `<repo>/<relative path>`** — e.g.
+   `` [`cli-tooling.md`](skills-public/cli-tooling.md) `` or
+   `` [`network.md`](skills-private/network.md) ``. Links resolve from the shared parent
+   directory holding both repos, so the same spelling works from either repo and from any
+   subdirectory. Never `./`, `../`, or absolute `file://` paths. The sole exception is the
+   per-agent profile files, which state each repository root once in full, since they are
+   loaded as global instructions with no implied working directory.
+6. **CLI discovery over enumeration** — document the *non-obvious* workflows, gotchas, and constraints. For the routine surface, point at `<tool> --help` rather than transcribing flag lists that will go stale.
+7. **No secrets inline** — reference the environment file that holds them (e.g. `~/.config/environment.d/…`), never the values themselves.
+8. **Verify before documenting** — confirm hostnames, container names, and versions against the live system rather than carrying forward stale claims.
 
 ---
 
@@ -47,10 +61,3 @@ These skill documents are compatible across agentic developer assistants and env
 - **Codex**: Include in workspace instructions or agent configuration.
 - **Antigravity**: Mount or reference from workspace `.agents/skills/` or global `~/.gemini/config/skills/`.
 - **Other AI Tools (Cursor, OpenCode, Aider, Devin)**: Include as persistent project rules or context files.
-6. **Link between skills as `<repo>/<relative path>`** — e.g.
-   `` [`cli-tooling.md`](skills-public/cli-tooling.md) `` or
-   `` [`network.md`](skills-private/network.md) ``. Links resolve from the shared parent
-   directory holding both repos, so the same spelling works from either repo and from any
-   subdirectory. Never `./`, `../`, or absolute `file://` paths. The sole exception is the
-   per-agent profile files, which state each repository root once in full, since they are
-   loaded as global instructions with no implied working directory.