docs: refresh agent roster + fix stale counts (203 agents / 14 divisions) (#562)

The README Stats and acknowledgements were stale (144 / 147 agents, "12
divisions") and 19 merged agents were missing from the division tables.

- Update both count statements to 203 agents across 14 divisions
- Add 19 missing roster rows: Design (1), Engineering (4), Marketing (5),
  Project Management (1), Sales (1), Specialized (7)
- De-hardcode the Gemini CLI README ("61 Agency agents" -> "all Agency
  agents") so it can't go stale again

Verified: every on-disk agent is now linked in the README (0 missing).

Thanks to the contributors whose agents are now cataloged — @epowelljr,
@hedonnn, @Subhodip-Chatterjee, @Shiven0504, @DKFuH, @ahteshamsalamatansari,
@ahruslan17, @lz-googlefycy, @jmlozano1990, @kriptoburak — and everyone
building out The Agency.

Co-authored-by: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

integrations/gemini-cli/README.md

@@ -1,6 +1,6 @@
 # Gemini CLI Integration
 
-Packages all 61 Agency agents as a Gemini CLI extension. The extension
+Packages all Agency agents as a Gemini CLI extension. The extension
 installs to `~/.gemini/extensions/agency-agents/`.
 
 ## Install