Add Coming Soon admonitions for Reporting Agent

[atc964]

Summary

• Adds "Coming Soon" admonitions to all documentation pages that reference the Reporting Agent, which has not been built yet
• Follows the existing convention used for other Coming Soon features (e.g., Creative Management, Multi-Seller Orchestration)
• Touches three docs files: tools.md, agent-hierarchy.md, configuration.md

Changes

• docs/architecture/tools.md: Added "(Coming Soon)" to the Mermaid diagram subgraph label, the summary table Reporting row, and a full admonition block above the Reporting Tools section
• docs/architecture/agent-hierarchy.md: Added "Coming Soon" annotation in the Mermaid diagram for the Reporting Agent node, and a full admonition block above the Reporting Agent subsection
• docs/guides/configuration.md: Added "(Coming Soon)" to the Reporting Agent row in the agent temperature table

Test plan

• mkdocs build --strict passes with no errors
• Full test suite: 1064 passed (21 failures + 11 errors are pre-existing on main, unrelated to docs)

bead: buyer-89x

🤖 Generated with Claude Code