Add the SQA and QC framework and project instructions

Mount the framework as a submodule at framework/ (v0.4.0), add AGENTS.md and
the installed skill copies for Codex CLI (.agents/skills) and Claude Code
(.claude/skills).

.agents/skills/artifact/templates/SSD.md

@@ -0,0 +1,42 @@
+# @TITLE@
+
+## Metadata
+| Key | Value |
+| --- | --- |
+| ID | @ID@ |
+| CrossReference | @CROSSREF@ |
+| Language | @LANGUAGE@ |
+| Domain | @DOMAIN@ |
+
+## Version History
+| Date | Status | Author | Reviewer | Change | Commit |
+| --- | --- | --- | --- | --- | --- |
+| @DATE@ | Proposed | @AUTHOR@ | <reviewer S-ID> | Initial version | pending |
+
+---
+
+## Source Use Case
+
+<Use case name> ([UC-<n>]) — scenario: <main success scenario | named alternate>
+
+## Diagram
+
+```plantuml
+@startuml
+actor Actor as A
+participant ":System" as S
+A -> S : verbPhrase(param)
+S --> A : result
+@enduml
+```
+
+## System Operations
+
+| Step | Message | Parameters | Return | Use case step |
+| --- | --- | --- | --- | --- |
+
+## Lifecycle Notes
+
+---
+
+@LINKS@