[AAASM-3794] 📝 (docs): Python SDK container base image guide

[Chisanan232]

Description

Adds a new Python-SDK docs guide, Governed container base image, documenting the
ghcr.io/ai-agent-assembly/python:{3.12,3.13,3.14}-slim governed base image: what it bundles
(the aasm CLI + the agent-assembly SDK, so a containerized Python agent is governed with
no extra install), immutable vs moving tag families, a Dockerfile quick start, the optional
SDK_VERSION build-arg, and pinning best practices. Wires the page into the Guides section of
the mkdocs.yml nav and adds a row to the Guides index table.

Type of Change

• 📚 Documentation update

Breaking Changes

• No

Related Issues

• Related JIRA ticket: AAASM-3794

Testing

• No tests required (docs-only change)
• Validated mkdocs.yml parses (custom !!python/name: tags handled) and the new nav entry
  resolves under Guides.
• Confirmed every relative link in the new page targets an existing docs file
  (../quick-start.md, ../compatibility/runtime.md, sibling guides).

Checklist

• Code follows project style guidelines
• Self-review completed
• Documentation updated if needed
• All tests passing (n/a — docs only)

Closes AAASM-3794

[Chisanan232]

Claude Code — review result

1. CI — ✅ all green (4 success, 2 skipped). The mkdocs build job (the real link/nav check) passes with the new page wired in.

2. Scope (AAASM-3794) — ✅ complete. Adds docs/guides/container-base-image.md — Python-tailored: the python:{3.12,3.13,3.14}-slim image (bundles aasm + importable agent-assembly), the immutable-vs-moving tag table, a FROM quick start, the optional SDK_VERSION, best practices, and "See also" links to the core guide + ADR 0009. Wired into the mkdocs Guides nav + the guides index table.

3. Side effects — ✅ none. Pure additive docs (+141/-0): a new page + one mkdocs.yml nav line + one guides-index row. No code; existing pages untouched.

Merge note: the "See also" GitHub links to the core guide/ADR resolve once agent-assembly #1257/#1261 merge — so merge this after those. Ready to approve.