feat: compress standalone release binaries and update installer scripts

[benwu95]

概述 (Overview)

本 PR 解決了 Bun 編譯出的 standalone binary 檔案體積偏大（Linux/Windows 約 90 MB，macOS 約 60-67 MB）的問題。
藉由調整 GitHub Release pipeline 管線將執行檔自動進行 .tar.gz 與 .zip 打包壓縮，並更新安裝腳本 install.sh 與 install.ps1 自動下載並解壓縮，成功將分發下載體積降低 60% 以上（約降至 26 MB），提升使用者安裝體驗與頻寬效率。

需求與驗收準則 (Requirements & Acceptance Criteria)

• REQ-CLI-001: Standalone Binary Compilation and Packaging for Multi-Platform
  • 在 GitHub 發布 Release 時，自動編譯 Linux/macOS/Windows 獨立執行檔，完成 macOS 的 codesign，並對其進行自動壓縮封裝。
• SC-1: Release Assets
  • 發布的 assets 內包含 prospec-linux-x64.tar.gz、prospec-macos-arm64.tar.gz、prospec-macos-x64.tar.gz、prospec-windows-x64.zip，解壓後可正常直接執行。

影響模組 (Affected Modules)

Module	Impact	Description
(none)	-	本次變更為 CI/CD 與安裝腳本等 Tooling 調整，未修改 TypeScript 模組原始碼。

驗證結果 (Verification & Quality)

• Quality Grade: S (Excellent)
• Tasks: 6/6 (100% completion)
• Acceptance Criteria: 4/4 met
• Tests: Vitest E2E/unit suite 100% PASS (2096/2096)
• Prospec check: 11/11 checks PASS (0 fail, 0 warn)

[github-actions]

Prospec Check

Prospec drift check (structural — deterministic, zero LLM)

  PASS  req-references
  PASS  file-paths
  PASS  import-direction
  PASS  knowledge-health
  SKIP  task-completion — source unavailable: .prospec/changes/ not found (not version-controlled)
  PASS  dangling-prefix
  PASS  feature-modules
  PASS  mcp-readme-counts
  SKIP  review-provenance — source unavailable: .prospec/changes/ not found (not version-controlled)
  SKIP  metadata-completeness — source unavailable: .prospec/changes/ not found (not version-controlled)
  PASS  knowledge-size

Knowledge coverage: 6/6 modules documented

Checked 8/11 checks: 0 fail, 0 warn, 3 skipped (not counted as pass)
Semantic consistency: not-checked (run /prospec-review)
Report written: prospec-report.json

[github-actions]

Test Coverage

Metric	Coverage	Covered / Total
lines	96.75%	3161 / 3267
statements	96.14%	3466 / 3605
functions	96.15%	575 / 598
branches	93.59%	1928 / 2060