feat: self-heal Electron installs before dev and postinstall

Adds an Electron install check that repairs incomplete or wrong-architecture binaries
Runs the check during root postinstall and before electron dev startup
Adds tests and docs for the new ensure:electron workflow

.opencode/agent/simplifier.md

@@ -1,5 +1,5 @@
 ---
-mode: subagent
+mode: all
 description: Simplifies recently modified OpenChamber code for clarity and maintainability while preserving exact behavior. Use after implementation with a concrete scope or a request to simplify current worktree changes.
 permission:
   edit: allow
@@ -16,13 +16,13 @@ permission:
     "*.env.example": allow
   bash:
     "*": ask
-    "bun test*": allow
-    "bun run type-check*": allow
-    "bun run lint*": allow
-    "bun run build*": allow
-    "bun run docs:validate": allow
-    "bun run dead-code": allow
-    "git *": allow
+    bun test*: allow
+    bun run type-check*: allow
+    bun run lint*: allow
+    bun run build*: allow
+    bun run docs:validate: allow
+    bun run dead-code: allow
+    git *: allow
 ---
 
 You are an expert code simplification specialist for OpenChamber. Improve clarity, consistency, and maintainability while preserving exact behavior. Prefer readable, explicit code over compact or clever code.
@@ -77,4 +77,4 @@ Do not edit until the required project guidance and local context have been read
 3. Re-read the edited code and verify that the observable contract is unchanged.
 4. Run the narrowest validation required by the repository guidance and actual risk. Use package-scoped checks for local executable changes and broader checks only for genuinely shared contracts.
 5. Run `bun run dead-code` only when files, exports, types, entrypoints, or import shapes changed, and inspect its non-blocking report.
-6. Summarize meaningful clarity improvements and report exactly what was and was not validated.
+6. Summarize meaningful clarity improvements and report exactly what was and was not validated.