fix(showcase): Capability Map internal links resolve under the page route

[yinlianghui]

Summary

Internal links in the Showcase Capability Map use relative paths and resolve underneath the current page route, leading to “Page not found”.

Found incidentally during the #2678 UI follow-up on framework baseline 98874656ffc50ce1531af52346228ffcdda73fba.

Reproduction

1. Open the Showcase Capability Map.
2. Click the Projects (backbone) capability link.
3. Repeat after returning to the Capability Map.

Observed in 2/2 attempts:

• Expected destination: /apps/com.objectstack.showcase/showcase_project
• Actual destination: a nested path under the current /page/... route, ending in /page/apps/com.objectstack.showcase/showcase_project
• Result: “Page not found”

Likely cause and scope

examples/app-showcase/src/ui/pages/capability-map.page.ts supplies relative internal paths such as apps/... and docs/..., and the shared card renders them directly as anchor href values.

The tested Projects (backbone) link is confirmed broken. Other internal apps/... and docs/... entries appear to share the same path-construction risk and should be audited.

Suggested regression coverage

Add a navigation test that enumerates all internal Capability Map links and asserts that each resolves from the application root to a valid page.

[yinlianghui]

稳定复现截图（#2678 测试中的附带发现）

固定 framework：98874656ffc50ce1531af52346228ffcdda73fba。

复现规则：

1. 打开 Showcase Capability Map。
2. 点击 Projects (backbone)。
3. 返回 Capability Map 后再次执行。

2/2 均从当前 /page/... 路由拼接出嵌套的 /page/apps/... URL并显示 Page not found。判定重点是内部链接必须从应用根路径解析，而不是相对于当前 page route 拼接。该问题与 #2678 的导入功能独立，仅作为测试附带发现记录。

固定 commit 下的完整证据与报告

[yinlianghui]

独立 UI 重现审计补充（2026-07-11）

固定 framework 98874656ffc50ce1531af52346228ffcdda73fba、ObjectUI 80901aad44ff3beeaf7882ec3367da934325b2f2，全新 --fresh backend + 全新登录会话，本轮仅点击一次：

• 起始 URL：/apps/com.example.showcase/page/showcase_capability_map
• 点击时 href：apps/com.example.showcase/showcase_project
• 实际 URL：/apps/com.example.showcase/page/apps/com.example.showcase/showcase_project
• UI 终态：Page not found

本轮 1/1 与既有结果一致。另需更正文中的 Expected：本固定 Showcase app id 是 com.example.showcase，因此预期根路径应为 /apps/com.example.showcase/showcase_project；正文当前写的 /apps/com.objectstack.showcase/showcase_project 与本 baseline 不一致。问题本身仍是相对 href 被拼到当前 /page/... 路由下，与 #2678 独立。