readme: tighten cost claim and agent copy

* readme: tighten cost claim and agent integration copy

- "up to 40%" → "40%+" (more direct)
- "normal file-reading tools" → "native search & file reading tools" (more precise)

* readme: qualify cost claim with benchmark context

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

* revert: restore original headline copy

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

---------

Co-authored-by: Grey Newell <greyshipscode@gmail.com>
Co-authored-by: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: 3 people

README.md

@@ -29,7 +29,7 @@ Uploads your repo to the Supermodel API, builds a full call graph, and writes `.
 
 **2. Your agent reads the graph automatically**
 
-`.graph` files are plain text. Any agent that can read files, including Claude Code, Cursor, Copilot, and Windsurf, picks them up automatically through their normal file-reading and search tools. No configuration needed on the agent side.
+`.graph` files are plain text. Any agent that can read files — Claude Code, Cursor, Copilot, Windsurf — picks them up automatically through its native search & file reading tools. No configuration needed on the agent side.
 
 **3. Ask anything**