## Why

The server management card action menu currently opens inside the card as a large vertical command stack, which obscures operational data and makes the card feel broken. The same card stat tiles render label/value text over busy translucent materials, so placeholder values such as `--` and labels like 玩家, TPS, 延迟, and 任务 lose contrast against uploaded or magical-girl backgrounds.

## What Changes

- Replace the in-card runtime action stack with a compact anchored overlay that does not resize or reflow server cards.
- Keep runtime actions platform-mediated and unchanged while closing the overlay on outside click, Escape, and action selection.
- After an operator selects a runtime action, show a modal task flow with stage progress for code pull, environment install/check, dependency download, compile/build, packaging, queued jobs, and final success/failure.
- Increase server card stat readability with stronger token-driven material, label contrast, value contrast, and text shadow that works across black mecha, magical-girl, and uploaded backgrounds.
- Remove misleading whole-card pointer affordance so only actual controls look clickable.

## Impact

- Affected root: `platform_web/`.
- Expected files: `platform_web/pages/ServersPage.tsx`, `platform_web/pages/ServerDetailPage.tsx`, `platform_web/components/RuntimeTaskProgress.tsx`, `platform_web/theme/base.css`, and focused rendering/style contract tests if useful.
- No platform, run, plugin, lifecycle, authorization, credential, or API behavior changes.
- Verification: focused frontend tests/typecheck, `scripts/check-structure.sh`, `openspec validate fix-server-card-action-menu --strict`, and browser walkthrough of 服务器管理.