fix: use real slotignored keyword instead of "None -- reason" text

Tested directly: slotignored is a recognized sentinel that excludes
a slot from the active/scored denominator entirely (verified:
active dropped 21->20 on a single-field test). "None -- reason"
text was just counted as populated content -- same 100% Trophy
result, but via the wrong mechanism. Trailing YAML comments after
slotignored are stripped by the parser (tool sees the clean
keyword) but preserved for human readers on GitHub -- combines
correct tool semantics with the explanatory context that was
missing from the original auto-generated slotignored spam.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

Author: Wolfe-Jam

project.faf

@@ -11,13 +11,13 @@ stack:
   backend: Node.js (stdio MCP server stub)
   api_type: MCP (JSON-RPC 2.0 over stdio)
   cicd: GitHub Actions (typecheck + demo run, verified green)
-  frontend: None — stdio reference implementation, no UI layer
-  css_framework: None — no UI
-  ui_library: None — no UI
-  state_management: None — stateless demo, no state to manage
-  database: None — no persistence layer
-  connection: None — no database
-  hosting: None — reference implementation, not a deployed service
+  frontend: slotignored  # no UI layer — stdio reference implementation
+  css_framework: slotignored  # no UI
+  ui_library: slotignored  # no UI
+  state_management: slotignored  # stateless demo, no state to manage
+  database: slotignored  # no persistence layer
+  connection: slotignored  # no database
+  hosting: slotignored  # reference implementation, not a deployed service
 tech_stack:
   - TypeScript
   - "@modelcontextprotocol/sdk"