feat: New Template Library (#7062)

## Summary

Implement the new design for template library

## Changes

- What
  - New sort option: `Popular` and  `Recommended`
  - New category: `Popular`, leverage the `Popular` sorting
  - Support add category stick to top of the side bar 
- Support template customized visible in different platform by
`includeOnDistributions` field

### How to make `Popular` and `Recommended` work

Add usage-based ordering to workflow templates with position bias
correction, manual ranking (searchRank), and freshness boost.

New sort modes:
- "Recommended" (default): usage × 0.5 + searchRank × 0.3 + freshness ×
0.2
- "Popular": usage × 0.9 + freshness × 0.1

## Screenshots (if applicable)

New default ordering:

<img width="1812" height="1852" alt="Selection_2485"
src="https://github.com/user-attachments/assets/8f4ed6e9-9cf4-43a8-8796-022dcf4c277e"
/>

┆Issue is synchronized with this [Notion
page](https://www.notion.so/PR-7062-feat-usage-based-template-ordering-2bb6d73d365081f1ac65f8ad55fe8ce6)
by [Unito](https://www.unito.io)

Popular category:

<img width="281" height="283" alt="image"
src="https://github.com/user-attachments/assets/fd54fcb8-6caa-4982-a6b6-1f70ca4b31e3"
/>

---------

Co-authored-by: Yourz <crazilou@vip.qq.com>
Co-authored-by: GitHub Action <action@github.com>

src/stores/templateRankingStore.ts

@@ -0,0 +1,66 @@
+/**
+ * Store for template ranking scores.
+ * Loads pre-computed usage scores from static JSON.
+ * Internal ranks come from template.searchRank in index.json.
+ * See docs/TEMPLATE_RANKING.md for details.
+ */
+
+import { defineStore } from 'pinia'
+import { ref } from 'vue'
+
+export const useTemplateRankingStore = defineStore('templateRanking', () => {
+  const largestUsageScore = ref<number>()
+
+  const normalizeUsageScore = (usage: number): number => {
+    return usage / (largestUsageScore.value ?? usage)
+  }
+
+  /**
+   * Compute freshness score based on template date.
+   * Returns 1.0 for brand new, decays to 0.1 over ~6 months.
+   */
+  const computeFreshness = (dateStr: string | undefined): number => {
+    if (!dateStr) return 0.5 // Default for templates without dates
+
+    const date = new Date(dateStr)
+    if (isNaN(date.getTime())) return 0.5
+
+    const daysSinceAdded = (Date.now() - date.getTime()) / (1000 * 60 * 60 * 24)
+    return Math.max(0.1, 1.0 / (1 + daysSinceAdded / 90))
+  }
+
+  /**
+   * Compute composite score for "default" sort.
+   * Formula: usage × 0.5 + internal × 0.3 + freshness × 0.2
+   */
+  const computeDefaultScore = (
+    dateStr: string | undefined,
+    searchRank: number | undefined,
+    usage: number = 0
+  ): number => {
+    const internal = (searchRank ?? 5) / 10 // Normalize 1-10 to 0-1
+    const freshness = computeFreshness(dateStr)
+
+    return normalizeUsageScore(usage) * 0.5 + internal * 0.3 + freshness * 0.2
+  }
+
+  /**
+   * Compute composite score for "popular" sort.
+   * Formula: usage × 0.9 + freshness × 0.1
+   */
+  const computePopularScore = (
+    dateStr: string | undefined,
+    usage: number = 0
+  ): number => {
+    const freshness = computeFreshness(dateStr)
+
+    return normalizeUsageScore(usage) * 0.9 + freshness * 0.1
+  }
+
+  return {
+    largestUsageScore,
+    computeFreshness,
+    computeDefaultScore,
+    computePopularScore
+  }
+})