docs: update build and formatting instructions in AGENT.md

AGENT.md

@@ -56,10 +56,21 @@
 
 ### Fix build problems
 
-Use this plan with sequential thinking:
-- Check the project using `TERM=dumb cargo check`
-- Identify the cause of any errors and warnings
-- If there are no errors or warnings, stop
-- If there are errors are warnings, create a plan to fix errors and warnings
-- Fix the files one at a time, not in parallel
-- Use the `write_file` tool to output the complete version of the corrected file
+1. Build the project: `TERM=dumb cargo build`.
+2. If there are errors or warnings, create a new sub agent (expert rust developer) that uses the `TERM=dumb cargo build` output as input, planned using strategic thinking.
+   a. Read all affected files
+   d. Plan the fixes using strategic thinking:
+      - Read other files if they provide context or examples
+      - Look up relevant API information
+      - Do not downgrade versions
+      - Preserve functionality
+      - Use `TERM=dumb cargo fix` if appropriate.
+      - Prefer the `write_file` tool if there is evidence of double escaping
+      - You must generate the full file contents when using `write_file` or it will be truncated.
+   c. Return the list of files modified
+3. If any files were modified, loop back to 1.
+
+### Fix formatting
+
+1. Format the project the project: `TERM=dumb cargo fmt`
+2. Continue with the fix build problems procedure.