Remove route-guard, Use busy? as the Guard in ui_routing2

Field	Value
Status	Done
Priority	P1
Created	2026-02-18
Completed	2026-02-18
Owner	AI

Context

ui_routing2.cljc has two overlapping guard mechanisms: the original busy? (boolean, from ro/busy? component option) and the newer route-guard (keyword denial reason, from ro/route-guard component option). The route-guard function checks ro/route-guard first, then falls back to ro/busy?, and stores a ::denial-reason keyword in the data model.

This is redundant. The statechart already tracks what state the system is in — the active configuration tells you which component blocked routing, and that component's own state is already visible in app state. A separate denial reason code duplicates information the statechart already has.

Simplify: use busy? as the sole guard predicate. Remove route-guard, ::denial-reason, and the ro/route-guard component option.

Requirements

1. Remove route-guard function from ui_routing2.cljc
2. Remove ro/route-guard component option from ui_routes_options.cljc
3. Remove ::denial-reason storage from record-failed-route!
4. Remove denial-reason public function from ui_routing2.cljc
5. The routes guard transition uses busy? as its :cond
6. Update demo (routing-demo2 ui.cljs) to remove denial-reason reference

Approach

ui_routing2.cljc

• Line 300-332: Delete route-guard function
• Line 334-339: Simplify record-failed-route! — only store ::failed-route-event, remove ::denial-reason assignment
• Line 341-345: Simplify clear-override! — remove ::denial-reason clearing
• Line 462: Change :cond route-guard to :cond busy?
• Lines 572-577: Delete denial-reason public function

ui_routes_options.cljc

• Lines 36-40: Delete route-guard def

routing-demo2/ui.cljs

• Line 231: Remove or replace (ur2/denial-reason this session-id) reference

Key Files

File	Change
src/main/com/fulcrologic/statecharts/integration/fulcro/ui_routing2.cljc	Remove route-guard, denial-reason; use busy? as guard
src/main/com/fulcrologic/statecharts/integration/fulcro/ui_routes_options.cljc	Remove ro/route-guard
src/routing-demo2/com/fulcrologic/statecharts/routing_demo2/ui.cljs	Remove denial-reason usage

Verification

1. Existing ui-routes-test tests pass (they don't reference route-guard or denial-reason)
2. routing-demo2 compiles without errors
3. busy? correctly blocks routing when a component's ro/busy? returns true