fix: remove invalid ;; comments from template_with_symbols_expanded.kicad_sch

PROBLEM
-------
Upstream commit b98c94b added 7 comment lines (;; PASSIVES, ;; SEMICONDUCTORS,
;; INTEGRATED CIRCUITS, ;; CONNECTORS, ;; POWER/REGULATORS, ;; MISC,
;; TEMPLATE INSTANCES) to template_with_symbols_expanded.kicad_sch.

KiCAD's S-expression parser does NOT support any comment syntax.
It expects every non-empty line to begin with '('. These comments caused
KiCAD 9 to refuse opening any schematic generated from this template:

  Expecting '(' in <file>.kicad_sch, line 8, offset 5

AFFECTED USERS
--------------
Any project whose .kicad_sch was generated by the MCP server after upstream
commit b98c94b and before this fix contains the same invalid lines. Those
files must be repaired manually: open the .kicad_sch in a text editor and
delete every line beginning with ';;'.

FIX
---
Remove all 7 ;; lines from the template. No functional change — the comments
provided no information that is not already evident from the symbol names.

ALSO
----
CHANGELOG: add critical bug-fix entry for this regression under v2.2.2-alpha

CHANGELOG.md

@@ -40,6 +40,16 @@ All notable changes to the KiCAD MCP Server project are documented here.
   format version `20250114` (KiCAD 9) after upstream commit `2b38796` accidentally downgraded
   both files to `20240101`. KiCAD 9 rejects schematics with outdated version numbers.
 
+- **CRITICAL: `template_with_symbols_expanded.kicad_sch`**: removed 7 invalid `;;` comment
+  lines introduced by upstream commit `b98c94b`. KiCAD's S-expression parser does not support
+  any comment syntax — it expects every non-empty, non-whitespace line to start with `(`.
+  The comments (`;; PASSIVES`, `;; SEMICONDUCTORS`, `;; INTEGRATED CIRCUITS`, `;; CONNECTORS`,
+  `;; POWER/REGULATORS`, `;; MISC`, `;; TEMPLATE INSTANCES (...)`) caused KiCAD 9 to reject
+  every schematic created from this template with a hard parse error:
+  > `Expecting '(' in <file>.kicad_sch, line 8, offset 5`
+  **Action required for existing projects:** delete every line beginning with `;;` from any
+  `.kicad_sch` file created between upstream commit `b98c94b` and this fix.
+
 ### Maintenance
 
 - `.gitignore`: added `*.kicad_pcb.bak`, `*.kicad_pro.bak` alongside existing `-bak` variants;