Add git version control panel and LAN hosting support

- Git modal (⎇ Git button): commit all diagrams as JSON to diagrams/ folder,
  push to remote, view history, restore any diagram from any past commit
- Diagrams exported to diagrams/{id}_{name}.json on each commit so diffs are
  human-readable and individual diagrams can be restored independently
- backend/run.py: changed host to 0.0.0.0 for LAN access

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

backend/app/main.py

@@ -7,7 +7,7 @@ from fastapi.staticfiles import StaticFiles
 from sqlalchemy import text, inspect as sa_inspect
 
 from .database import Base, engine, SessionLocal
-from .routers import bundles, connectors, diagrams, devices, export, octopart, views, wires
+from .routers import bundles, connectors, diagrams, devices, export, git_mgr, octopart, views, wires
 
 Base.metadata.create_all(bind=engine)
 
@@ -70,6 +70,7 @@ app.include_router(views.router,     prefix="/api/views")
 app.include_router(octopart.router,  prefix="/api/octopart")
 app.include_router(export.router,    prefix="/api/export")
 app.include_router(connectors.router, prefix="/api/connectors")
+app.include_router(git_mgr.router,   prefix="/api/git")
 
 FRONTEND_DIR = os.path.normpath(
     os.path.join(os.path.dirname(__file__), "..", "..", "frontend")

backend/app/routers/git_mgr.py

@@ -0,0 +1,235 @@
+import json
+import re
+import subprocess
+from pathlib import Path
+from typing import Optional
+
+from fastapi import APIRouter, Depends, HTTPException
+from pydantic import BaseModel
+from sqlalchemy.orm import Session
+
+from .. import models
+from ..database import get_db
+
+router = APIRouter(tags=["git"])
+
+# ── Helpers ───────────────────────────────────────────────────────────────────
+
+def _run(*args, cwd: Path) -> subprocess.CompletedProcess:
+    return subprocess.run(
+        ["git", *args],
+        capture_output=True, text=True, cwd=str(cwd), timeout=30,
+    )
+
+
+def _repo_root() -> Path:
+    backend_dir = Path(__file__).parent.parent.parent
+    r = _run("rev-parse", "--show-toplevel", cwd=backend_dir)
+    if r.returncode != 0:
+        raise HTTPException(500, "Not in a git repository")
+    return Path(r.stdout.strip())
+
+
+def _diagrams_dir(repo_root: Path) -> Path:
+    d = repo_root / "diagrams"
+    d.mkdir(exist_ok=True)
+    return d
+
+
+def _safe_name(diagram_id: int, name: str) -> str:
+    safe = re.sub(r"[^\w\-]", "_", name)
+    return f"{diagram_id:04d}_{safe}.json"
+
+
+def _diagram_to_dict(diagram, db: Session) -> dict:
+    return {
+        "id": diagram.id,
+        "name": diagram.name,
+        "description": diagram.description or "",
+        "devices": [
+            {
+                "id": d.id, "device_type": d.device_type, "label": d.label,
+                "reference": d.reference, "x": d.x, "y": d.y,
+                "width": d.width, "height": d.height,
+                "properties": d.properties, "pins": d.pins,
+            }
+            for d in diagram.devices
+        ],
+        "wires": [
+            {
+                "id": w.id, "label": w.label,
+                "from_device_id": w.from_device_id, "from_pin": w.from_pin,
+                "to_device_id": w.to_device_id, "to_pin": w.to_pin,
+                "color_primary": w.color_primary, "color_stripe": w.color_stripe,
+                "gauge": w.gauge, "length": w.length, "length_unit": w.length_unit,
+                "notes": w.notes, "waypoints": w.waypoints or [],
+                "twisted_pair": bool(w.twisted_pair), "twist_pitch": w.twist_pitch,
+                "shielded": bool(w.shielded), "show_size_label": bool(w.show_size_label),
+            }
+            for w in diagram.wires
+        ],
+    }
+
+
+def _import_data(data: dict, db: Session, name_override: Optional[str] = None) -> models.Diagram:
+    new_diag = models.Diagram(
+        name=name_override or data.get("name", "Restored Diagram"),
+        description=data.get("description", ""),
+    )
+    db.add(new_diag)
+    db.flush()
+    id_map = {}
+    for dev in data.get("devices", []):
+        nd = models.Device(
+            diagram_id=new_diag.id,
+            device_type=dev.get("device_type", "generic"),
+            label=dev.get("label", ""),
+            reference=dev.get("reference", ""),
+            x=dev.get("x", 100), y=dev.get("y", 100),
+            width=dev.get("width", 120), height=dev.get("height", 60),
+            properties=dev.get("properties", {}),
+            pins=dev.get("pins", []),
+        )
+        db.add(nd)
+        db.flush()
+        if "id" in dev:
+            id_map[dev["id"]] = nd.id
+    for w in data.get("wires", []):
+        nw = models.Wire(
+            diagram_id=new_diag.id,
+            label=w.get("label", ""),
+            from_device_id=id_map.get(w.get("from_device_id")),
+            from_pin=w.get("from_pin", ""),
+            to_device_id=id_map.get(w.get("to_device_id")),
+            to_pin=w.get("to_pin", ""),
+            color_primary=w.get("color_primary", "#FF0000"),
+            color_stripe=w.get("color_stripe"),
+            gauge=w.get("gauge", "18 AWG"),
+            length=w.get("length"),
+            length_unit=w.get("length_unit", "in"),
+            notes=w.get("notes", ""),
+            waypoints=w.get("waypoints", []),
+            twisted_pair=w.get("twisted_pair", False),
+            twist_pitch=w.get("twist_pitch", 16.0),
+            shielded=w.get("shielded", False),
+            show_size_label=w.get("show_size_label", False),
+        )
+        db.add(nw)
+    db.commit()
+    db.refresh(new_diag)
+    return new_diag
+
+
+# ── Endpoints ─────────────────────────────────────────────────────────────────
+
+@router.get("/status")
+def git_status():
+    repo_root = _repo_root()
+
+    branch_r = _run("rev-parse", "--abbrev-ref", "HEAD", cwd=repo_root)
+    branch = branch_r.stdout.strip() if branch_r.returncode == 0 else "unknown"
+
+    status_r = _run("status", "--porcelain", cwd=repo_root)
+    changed = [l for l in status_r.stdout.splitlines() if l.strip()]
+
+    ahead_r = _run("rev-list", "--count", "@{u}..HEAD", cwd=repo_root)
+    ahead = int(ahead_r.stdout.strip()) if ahead_r.returncode == 0 and ahead_r.stdout.strip().isdigit() else 0
+
+    return {
+        "branch": branch,
+        "is_clean": len(changed) == 0,
+        "changed_count": len(changed),
+        "commits_ahead": ahead,
+    }
+
+
+@router.get("/log")
+def git_log():
+    repo_root = _repo_root()
+    r = _run("log", "--pretty=format:%H|%h|%s|%an|%ai", "-30", cwd=repo_root)
+    if r.returncode != 0:
+        return []
+    entries = []
+    for line in r.stdout.splitlines():
+        parts = line.split("|", 4)
+        if len(parts) == 5:
+            entries.append({
+                "hash": parts[0], "short": parts[1],
+                "message": parts[2], "author": parts[3], "date": parts[4],
+            })
+    return entries
+
+
+class CommitBody(BaseModel):
+    message: str
+
+
+@router.post("/commit")
+def git_commit(body: CommitBody, db: Session = Depends(get_db)):
+    if not body.message.strip():
+        raise HTTPException(400, "Commit message required")
+    repo_root = _repo_root()
+    diagrams_dir = _diagrams_dir(repo_root)
+
+    # Export all diagrams to diagrams/ folder
+    diagrams = db.query(models.Diagram).all()
+    for diagram in diagrams:
+        data = _diagram_to_dict(diagram, db)
+        fname = _safe_name(diagram.id, diagram.name)
+        (diagrams_dir / fname).write_text(json.dumps(data, indent=2), encoding="utf-8")
+
+    add_r = _run("add", "diagrams/", cwd=repo_root)
+    if add_r.returncode != 0:
+        raise HTTPException(500, f"git add failed: {add_r.stderr}")
+
+    commit_r = _run("commit", "-m", body.message.strip(), cwd=repo_root)
+    if commit_r.returncode != 0:
+        out = commit_r.stdout + commit_r.stderr
+        if "nothing to commit" in out:
+            return {"status": "nothing_to_commit", "output": "Nothing to commit — diagrams unchanged since last commit"}
+        raise HTTPException(500, f"git commit failed: {commit_r.stderr}")
+
+    return {"status": "committed", "output": commit_r.stdout.strip()}
+
+
+@router.post("/push")
+def git_push():
+    repo_root = _repo_root()
+    r = _run("push", cwd=repo_root)
+    if r.returncode != 0:
+        raise HTTPException(500, f"git push failed: {r.stderr.strip()}")
+    return {"status": "pushed", "output": (r.stdout + r.stderr).strip()}
+
+
+@router.get("/history/{commit_hash}")
+def git_history_files(commit_hash: str):
+    repo_root = _repo_root()
+    r = _run("ls-tree", "--name-only", commit_hash, "diagrams/", cwd=repo_root)
+    if r.returncode != 0:
+        return {"files": []}
+    files = [f for f in r.stdout.splitlines() if f.endswith(".json")]
+    return {"files": files}
+
+
+class RestoreBody(BaseModel):
+    commit_hash: str
+    filepath: str   # e.g. "diagrams/0001_My_Diagram.json"
+    name: Optional[str] = None
+
+
+@router.post("/restore")
+def git_restore(body: RestoreBody, db: Session = Depends(get_db)):
+    repo_root = _repo_root()
+    r = _run("show", f"{body.commit_hash}:{body.filepath}", cwd=repo_root)
+    if r.returncode != 0:
+        raise HTTPException(404, f"File not found in that commit")
+
+    try:
+        data = json.loads(r.stdout)
+    except json.JSONDecodeError:
+        raise HTTPException(500, "Invalid JSON in git history")
+
+    short_hash = body.commit_hash[:7]
+    name = body.name or f"{data.get('name', 'Diagram')} (restored {short_hash})"
+    new_diag = _import_data(data, db, name_override=name)
+    return {"id": new_diag.id, "name": new_diag.name}