feat(portal): "Copy client link" — generate/copy/revoke shareable links from the project page

No-CLI way to get a real shareable magic link (/portal/enter/<token>) for a
project's client. Project page gets a "Copy client link" button next to the
preview; opens a modal that lists active links (with revoke), generates a fresh
one, and copies it to the clipboard.

Backend (operator, internal /projects/*):
- POST /projects/{id}/portal-link  -> mint a fresh token, return the full URL
  (built from request.base_url so it uses the operator's host).
- GET  /projects/{id}/portal-links -> list active links (label/created/last-used).
- POST /projects/{id}/portal-link/{tid}/revoke -> revoke one (scoped to the
  project's client).

Refactor: split ensure_project_client() + mint_link_token() out of
provision_preview_session() so minting a shareable link and the preview cookie
share one provisioning path.

Verified: ensure/mint persistence across commits + sessions, minted link resolves,
token stored hashed, second mint = distinct active link (4/4); compiles; share
script balances; detail.html parses.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

backend/main.py

@@ -432,6 +432,60 @@ async def project_portal_preview(project_id: str, db: Session = Depends(get_db))
     return resp
 
 
+@app.post("/projects/{project_id}/portal-link")
+async def project_portal_link_create(project_id: str, request: Request, db: Session = Depends(get_db)):
+    """Mint a fresh shareable client link for this project's client. Returns the
+    full /portal/enter/<token> URL (shown once). Operator-only (internal app)."""
+    from backend.models import Project
+    from backend.portal_auth import ensure_project_client, mint_link_token
+    project = db.query(Project).filter_by(id=project_id).first()
+    if not project:
+        return JSONResponse(status_code=404, content={"detail": "Project not found"})
+    client = ensure_project_client(project, db)
+    raw = mint_link_token(client, db, label="shared link")
+    url = str(request.base_url).rstrip("/") + f"/portal/enter/{raw}"
+    return {"url": url, "client_name": client.name}
+
+
+@app.get("/projects/{project_id}/portal-links")
+async def project_portal_links_list(project_id: str, db: Session = Depends(get_db)):
+    """List active (non-revoked) shareable links for this project's client."""
+    from backend.models import Project, ClientAccessToken, Client
+    project = db.query(Project).filter_by(id=project_id).first()
+    if not project or not project.client_id:
+        return {"client_name": None, "links": []}
+    client = db.query(Client).filter_by(id=project.client_id).first()
+    toks = (db.query(ClientAccessToken)
+            .filter_by(client_id=project.client_id, revoked_at=None)
+            .order_by(ClientAccessToken.created_at.desc()).all())
+    return {
+        "client_name": client.name if client else None,
+        "links": [{
+            "id": t.id, "label": t.label,
+            "created_at": t.created_at.isoformat() if t.created_at else None,
+            "last_used_at": t.last_used_at.isoformat() if t.last_used_at else None,
+        } for t in toks],
+    }
+
+
+@app.post("/projects/{project_id}/portal-link/{token_id}/revoke")
+async def project_portal_link_revoke(project_id: str, token_id: str, db: Session = Depends(get_db)):
+    """Revoke one shareable link (scoped to this project's client). Kills the link
+    and any live session minted from it on the next request."""
+    from datetime import datetime as _dt
+    from backend.models import Project, ClientAccessToken
+    project = db.query(Project).filter_by(id=project_id).first()
+    if not project or not project.client_id:
+        return JSONResponse(status_code=404, content={"detail": "Not found"})
+    tok = db.query(ClientAccessToken).filter_by(id=token_id, client_id=project.client_id).first()
+    if not tok:
+        return JSONResponse(status_code=404, content={"detail": "Link not found"})
+    if not tok.revoked_at:
+        tok.revoked_at = _dt.utcnow()
+        db.commit()
+    return {"ok": True}
+
+
 @app.get("/projects/{project_id}/nrl/{location_id}", response_class=HTMLResponse)
 async def nrl_detail_page(
     request: Request,