Normalize whitespace in grid get_process_output to save tokens

Grid snapshots pad every row to the full terminal width and leave the
bottom of the screen blank, so MCP grid reads carried a lot of dead
whitespace. Add normalizeGridText (CRLF/lone-CR to LF, right-trim each
line, collapse blank runs to a single blank, drop leading/trailing
blanks) and apply it to the grid branch of GetProcessOutput only.
Stream output, raw output, and WaitForPattern matching are untouched.

Resolves the terminal-read newline/token-waste TODO item.

CHANGELOG.md

@@ -10,6 +10,11 @@ loosely follows [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 - MCP clients can now call `scratchpad_delete` with a scratchpad name
   to remove a shared project scratchpad.
 
+### Changed
+- Grid-mode `get_process_output` now returns whitespace-normalized
+  text to avoid sending padded terminal rows and repeated blank lines
+  over MCP.
+
 ### Fixed
 - Closing an agent now escalates from SIGTERM to SIGKILL when needed,
   so agents that ignore SIGTERM disappear from the running tab bar