feat(SCOPONE-0010): vendor agent assets and clean docs

.github/skills/timestamp/SKILL.md

@@ -0,0 +1,29 @@
+```skill
+---
+name: timestamp
+description: OS-agnostic ISO8601 timestamp generation for YAML files, logging, and any agent that needs the current time.
+---
+
+# Timestamp
+
+## Detect OS
+
+Check the user's OS from the environment info provided in the system prompt. Look for:
+- `Windows` → use PowerShell
+- `macOS` or `Linux` → use shell
+
+## Get Current ISO8601 Timestamp
+
+Run in terminal and capture output:
+
+| OS | Command |
+|----|---------|
+| Windows | `Get-Date -Format "yyyy-MM-ddTHH:mm:ss.fffZ"` |
+| macOS / Linux | `date -u +"%Y-%m-%dT%H:%M:%S.000Z"` |
+
+## Usage
+
+Wherever `{ISO8601}` appears in agent instructions, substitute with the actual output of the command above.
+
+For multiple timestamps in quick succession (e.g., populating a YAML file), run the command once and reuse the value within the same step.
+```