Extract high-current PCB lessons into a standalone design skill

Separate reusable current-path, Kelvin sensing, startup-state and routing
checks from the BMS case parameters, and include a project review template.

Constraint: Preserve project-specific limits and distinguish analysis from hardware tests.
Confidence: High for package structure and reviewed decision boundaries.
Scope-risk: Narrow; new standalone skill, no PCB changes.
Tested: Skill validator, relative links, market source configuration, read-only scenario review.
Not-tested: Remote authentication returned HTTP 401; no EDA or hardware execution.

.gitattributes

@@ -0,0 +1,5 @@
+* text=auto
+.gitattributes text eol=lf
+*.md text eol=lf
+*.yaml text eol=lf
+*.json text eol=lf