feat(project-bootstrap): add we're on Windows to default CLAUDE.md template

Pin every newly-bootstrapped project to Windows / PowerShell out of the box
by adding a fifth trigger line to the CLAUDE.md template. The line activates
the active-platform skill, which then governs all command/example output.

- skills/project-bootstrap/assets/CLAUDE.md.template: append `we're on Windows`
- skills/project-bootstrap/SKILL.md: sync the embedded preview in Step 5 and
  document the Linux/macOS substitution
- CLAUDE.md (this repo): backfill the line — was created from old template
- dist/project-bootstrap.skill: rebuilt
- .wiki/source/active-platform-decision.md: append "Wired into project-bootstrap"

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

.tasks/STATUS.md

@@ -3,6 +3,12 @@ _Updated: 2026-04-28_
 
 ## Done
 
+### project-bootstrap: include `active-platform` trigger in CLAUDE.md template
+- [x] Add `we're on Windows` line to `assets/CLAUDE.md.template`
+- [x] Update embedded preview in `SKILL.md` Step 5 (with note about Linux/macOS substitution)
+- [x] Backfill the line in this repo's own `CLAUDE.md`
+- [x] Rebuild + reinstall `project-bootstrap.skill`
+
 ### active-platform skill
 - [x] Draft `skills/active-platform/SKILL.md` (RU+EN triggers, default=Windows/PowerShell, palette=Win/Linux/mac)
 - [x] Fixed `build.sh` PS arg-passing bug (single-quotes were leaking into `-Names` value)