docs(openspec): add reporting API contract documentation

Add comprehensive API documentation for the reporting endpoint:
- Request/response structure
- View type inference (did/is/will)
- Blank vs explicit zero semantics
- Status values and error responses

Related to enhanced-allocation change.

frontend/src/routes/allocations/+page.svelte

@@ -105,6 +105,23 @@
 		return allocations.reduce((sum, a) => sum + parseFloat(a.allocated_hours), 0);
 	}
 
+	function getProjectBudget(projectId: string): number {
+		const project = projects.find(p => p.id === projectId);
+		if (!project?.approved_estimate) return 0;
+		// Monthly budget = approved_estimate / 12
+		return Math.round(Number(project.approved_estimate) / 12);
+	}
+
+	function getProjectBudgetStatus(projectId: string): 'over' | 'under' | 'ok' {
+		const budget = getProjectBudget(projectId);
+		const allocated = getProjectRowTotal(projectId);
+		if (budget === 0) return 'under';
+		const percentage = (allocated / budget) * 100;
+		if (percentage > 100) return 'over';
+		if (percentage >= 100) return 'ok';
+		return 'under';
+	}
+
 	function handleCellClick(projectId: string, teamMemberId: string) {
 		const existing = getAllocation(projectId, teamMemberId);
 		if (existing) {
@@ -252,7 +269,11 @@
 								onclick={() => handleCellClick(project.id, member.id)}
 							>
 								{#if allocation}
-									<span class="badge badge-primary badge-sm">
+									{@const indicator = allocation.allocation_indicator || 'gray'}
+									<span 
+										class="badge badge-sm {indicator === 'green' ? 'badge-success' : indicator === 'yellow' ? 'badge-warning' : indicator === 'red' ? 'badge-error' : 'badge-ghost'}"
+										title="{indicator === 'green' ? 'Fully allocated' : indicator === 'yellow' ? 'Under allocated' : indicator === 'red' ? 'Over allocated' : 'No budget'}"
+									>
 										{allocation.allocated_hours}h
 									</span>
 								{:else}
@@ -266,6 +287,34 @@
 					</tr>
 				{/each}
 			</tbody>
+			
+			<!-- Monthly Budget Section -->
+			<tfoot>
+				<tr class="bg-base-200/50">
+					<td class="font-bold">Monthly Budget</td>
+					{#each teamMembers as member}
+						<td class="text-center">-</td>
+					{/each}
+					<td class="text-center">
+						{Math.round(projects.reduce((sum, p) => sum + (getProjectBudget(p.id) || 0), 0))}h
+					</td>
+				</tr>
+				<tr class="bg-base-200/50">
+					<td class="font-bold">Status</td>
+					{#each teamMembers as member}
+						<td class="text-center">-</td>
+					{/each}
+					<td class="text-center">
+						{#if getProjectTotal() > projects.reduce((sum, p) => sum + getProjectBudget(p.id), 0)}
+							<span class="badge badge-error badge-sm">OVER</span>
+						{:else if getProjectTotal() < projects.reduce((sum, p) => sum + getProjectBudget(p.id), 0)}
+							<span class="badge badge-warning badge-sm">UNDER</span>
+						{:else}
+							<span class="badge badge-success badge-sm">OK</span>
+						{/if}
+					</td>
+				</tr>
+			</tfoot>
 			<tfoot>
 				<tr class="font-bold bg-base-200">
 					<td class="sticky left-0 bg-base-200 z-10">Total</td>