Fix: Add input_prompt display in decision cards

Previously, the frontend DecisionRecord type was missing the input_prompt
field that exists in the backend DecisionLog, causing the input context
sent to AI to not be displayed in the UI.

Changes:
- Add input_prompt field to DecisionRecord interface in both type files
- Add collapsible Input Prompt section in DecisionCard component
- Display input_prompt before AI Chain of Thought with blue styling
- Use same expand/collapse interaction pattern as CoT trace

Now users can view both the input context and AI's reasoning process
in the decision cards.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

web/src/types/index.ts

@@ -56,6 +56,7 @@ export interface DecisionAction {
 export interface DecisionRecord {
   timestamp: string;
   cycle_number: number;
+  input_prompt: string;
   cot_trace: string;
   decision_json: string;
   account_state: {