chore: restructure skills repo with new agents and skill bundles

- Add new skills: deep-dive, docs-rag, meta-creator, ppt-maker, sdlc
- Add agent configs: g-assistent, meta-creator, sdlc with prompt files
- Add reference docs for custom agents and skills specification
- Add utility scripts: install-agents.sh, orchestrate.py, puml2svg.sh
- Update README and commit-message skill config
- Remove deprecated skills: codereview, python, testing, typescript
- Add .gitignore

skills/commit-message/assets/architecture.puml

@@ -0,0 +1,24 @@
+@startuml commit-message-architecture
+skinparam componentStyle rectangle
+skinparam defaultFontName Arial
+skinparam backgroundColor #FAFAFA
+
+package "commit-message Skill" {
+  component "SKILL.md\n(instructions)" as SKILL
+  component "references/\nconventional-commits.md" as REF
+  component "evals/evals.json" as EVALS
+}
+
+package "Git Environment" {
+  database "Staged Changes\n(git index)" as INDEX
+  component "git commit" as GIT
+}
+
+actor Developer
+
+Developer --> SKILL : triggers skill
+SKILL --> REF : loads commit format rules
+SKILL --> INDEX : reads via git diff --cached
+SKILL --> Developer : proposes message
+Developer --> GIT : confirms & commits
+@enduml

skills/commit-message/assets/workflow.puml

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+@startuml commit-message-workflow
+skinparam defaultFontName Arial
+skinparam backgroundColor #FAFAFA
+
+actor Developer
+participant "commit-message\nSkill" as SKILL
+participant "git" as GIT
+
+Developer -> SKILL : "commit these changes"
+SKILL -> GIT : git status
+GIT --> SKILL : staged files list
+SKILL -> GIT : git diff --cached
+GIT --> SKILL : diff output
+SKILL -> SKILL : draft Conventional Commits message
+SKILL --> Developer : proposed message
+alt confirmed
+  Developer -> GIT : git commit -m "..."
+else refine
+  Developer -> SKILL : feedback
+  SKILL --> Developer : revised message
+end
+@enduml