refactor(frontend) : replace any types with concrete TypeScript types

Replace 9 occurrences of 'any' with proper types: HydraCollection, Task,
ClientTicketWrite, TimeEntryWrite across 7 components.

Ticket: T-023

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

frontend/pages/index.vue

@@ -471,7 +471,7 @@ const lineOptions = {
         legend: { display: false },
         tooltip: {
             callbacks: {
-                label: (ctx: any) => `${formatHours(ctx.raw)}`,
+                label: (ctx: { raw: unknown }) => `${formatHours(ctx.raw as number)}`,
             },
         },
     },
@@ -480,7 +480,7 @@ const lineOptions = {
             beginAtZero: true,
             grid: { color: '#f3f4f6' },
             ticks: {
-                callback: (value: any) => `${value}h`,
+                callback: (value: number | string) => `${value}h`,
             },
         },
         x: {