Move button actions to per-widget config, add hold-for-global-action

Next/back button assignment moves from a frame-level "Button
assignments" card into each widget's own gear-icon dialog, prefilled
with a sane default at creation (photos/calendar -> advance/back,
whiteboard/weather -> check_now, others -> none). At most one binding
per (widget, button) now -- cross-widget execution order never
mattered since each widget's action only touches its own state.

New firmware capability: holding NEXT or BACK past a configurable
duration (min 3s, server-side default) triggers a frame-wide action
instead of the per-widget short-press one -- cycling saved layouts,
refreshing all widgets, or freezing/unfreezing every photo widget (see
app/global_actions.py). Firmware next/back checks gain the same
hold-duration polling the combo button already had; the threshold
comes from the previous wake's /frame/config fetch (persisted in NVS),
since this wake's button decision happens before that request.

Not done here: firmware/version.txt is intentionally left unbumped --
this hasn't been built or hardware-tested (no ESP-IDF toolchain in this
environment), so no firmware release build should be triggered yet.

server/app/routers/api_frames.py

@@ -22,17 +22,16 @@ import time
 import httpx
 from fastapi import APIRouter, Depends, File, Form, HTTPException, Request, UploadFile
 from fastapi.responses import Response
-from pydantic import BaseModel
-from sqlalchemy import delete, select
+from sqlalchemy import select
 from sqlalchemy.orm import Session
 
 from .. import gitea_releases, grid, quiet_hours
 from ..auth import require_frame_control, require_frame_view, require_user_api
 from ..db import frame_locked, get_db
+from ..global_actions import GLOBAL_ACTIONS
 from ..image_pipeline import PALETTE_LABELS, hex_to_rgb
 from ..firmware import firmware_path, parse_app_version
-from ..models import BatteryLog, Frame, FrameButtonAction, Widget
-from ..widgets import WIDGET_TYPES
+from ..models import BatteryLog, Frame, Widget
 from .common import OVERDUE_FACTOR, battery_estimate_s, immich_client_for, immich_creds, valid_http_url
 from .device import render_frame_preview_png
 
@@ -45,6 +44,11 @@ MAX_REFRESH_INTERVAL_S = 86400
 
 ORIENTATIONS = ("landscape", "portrait", "landscape_flipped", "portrait_flipped")
 
+# See app/global_actions.py -- how long NEXT/BACK must be held before the
+# device treats it as a hold instead of a short press.
+MIN_HOLD_DURATION_MS = 3000
+MAX_HOLD_DURATION_MS = 10000
+
 
 def _reset_widget_layout_for_new_orientation(db: Session, frame_id: int, new_orientation: str) -> None:
     """A widget's x/y/w/h are grid cells relative to the OLD orientation's
@@ -101,6 +105,9 @@ def api_config_save(
     color_boost: float | None = Form(None),
     contrast_boost: float | None = Form(None),
     dither_strength: float | None = Form(None),
+    hold_duration_ms: int | None = Form(None),
+    next_hold_action: str | None = Form(None),
+    back_hold_action: str | None = Form(None),
     frame: Frame = Depends(require_frame_control),
     db: Session = Depends(get_db),
 ):
@@ -120,7 +127,14 @@ def api_config_save(
     _reset_widget_layout_for_new_orientation) -- widget placement is
     grid-cell-relative to the panel's long/short axis, which swaps on a
     landscape<->portrait change, so an old placement is usually not just
-    visually wrong but literally out of bounds on the new grid."""
+    visually wrong but literally out of bounds on the new grid.
+
+    hold_duration_ms/next_hold_action/back_hold_action configure hold-
+    for-global-action (see app/global_actions.py) -- a frame-wide
+    setting, not per-widget, hence living here rather than on
+    api_widgets.py's per-widget button-actions endpoint. An unrecognized
+    action value clears the binding rather than erroring, same posture
+    as this endpoint's other enum-ish fields (orientation, timezone)."""
     with frame_locked(db, frame.id) as cfg:
         if name is not None:
             cfg.name = name.strip()[:64] or cfg.name
@@ -168,6 +182,12 @@ def api_config_save(
             cfg.contrast_boost = max(0.0, min(2.0, contrast_boost))
         if dither_strength is not None:
             cfg.dither_strength = max(0.0, min(1.0, dither_strength))
+        if hold_duration_ms is not None:
+            cfg.hold_duration_ms = max(MIN_HOLD_DURATION_MS, min(MAX_HOLD_DURATION_MS, hold_duration_ms))
+        if next_hold_action is not None:
+            cfg.next_hold_action = next_hold_action if next_hold_action in GLOBAL_ACTIONS else None
+        if back_hold_action is not None:
+            cfg.back_hold_action = back_hold_action if back_hold_action in GLOBAL_ACTIONS else None
         cfg.stats_config_saves += 1
 
     return {"status": "saved"}
@@ -251,95 +271,6 @@ def api_frame_preview(
     return Response(content=png, media_type="image/png")
 
 
-BUTTONS = ("next", "back")
-
-
-@router.get("/api/frames/{frame_id}/buttons")
-def api_buttons_get(frame: Frame = Depends(require_frame_view), db: Session = Depends(get_db)):
-    """Everything the button-assignment UI needs in one call: every
-    widget on the frame with the actions its type supports (see
-    app/widgets/*.py's ACTIONS/ACTION_LABELS), plus each button's current
-    ordered list of (widget, action) bindings.
-
-    Includes each widget's placement (x/y/w/h) and the frame's grid
-    dimensions -- two widgets of the same type otherwise look identical
-    in the assignment UI's dropdowns (both just say "Photos"); the
-    client derives a position label ("top-left" etc.) from this to tell
-    them apart, the same way you'd tell them apart by eye on the Layout
-    canvas."""
-    cols, rows = grid.grid_dims(frame.orientation)
-    widgets = db.scalars(
-        select(Widget).where(Widget.frame_id == frame.id).order_by(Widget.sort_order)
-    ).all()
-    widget_options = [
-        {
-            "id": w.id,
-            "widget_type": w.widget_type,
-            "x": w.x, "y": w.y, "w": w.w, "h": w.h,
-            "actions": [
-                {"action": action, "label": label}
-                for action, label in getattr(WIDGET_TYPES.get(w.widget_type), "ACTION_LABELS", {}).items()
-            ],
-        }
-        for w in widgets
-    ]
-    result = {"widgets": widget_options, "grid": {"cols": cols, "rows": rows}}
-    for button in BUTTONS:
-        rows = db.scalars(
-            select(FrameButtonAction)
-            .where(FrameButtonAction.frame_id == frame.id, FrameButtonAction.button == button)
-            .order_by(FrameButtonAction.sort_order)
-        ).all()
-        result[button] = [{"id": r.id, "widget_id": r.widget_id, "action": r.action} for r in rows]
-    return result
-
-
-class ButtonActionItem(BaseModel):
-    widget_id: int
-    action: str
-
-
-class ButtonActionsRequest(BaseModel):
-    actions: list[ButtonActionItem]
-
-
-@router.put("/api/frames/{frame_id}/buttons/{button}")
-def api_buttons_save(
-    button: str, body: ButtonActionsRequest,
-    frame: Frame = Depends(require_frame_control), db: Session = Depends(get_db),
-):
-    """Replaces the whole ordered action list for one button in a single
-    call -- simpler and more atomic than separate add/remove/reorder
-    endpoints for what's normally a list of one to a handful of entries,
-    and the UI always has the full list in hand anyway (see
-    static/frame_config.js)."""
-    if button not in BUTTONS:
-        raise HTTPException(404, "No such button")
-    widgets_by_id = {w.id: w for w in db.scalars(select(Widget).where(Widget.frame_id == frame.id))}
-    for item in body.actions:
-        widget = widgets_by_id.get(item.widget_id)
-        if widget is None:
-            raise HTTPException(400, f"No such widget: {item.widget_id}")
-        module = WIDGET_TYPES.get(widget.widget_type)
-        if module is None or item.action not in module.ACTIONS:
-            raise HTTPException(
-                400, f"{widget.widget_type} widgets don't support the {item.action!r} action"
-            )
-    with frame_locked(db, frame.id):
-        db.execute(
-            delete(FrameButtonAction).where(
-                FrameButtonAction.frame_id == frame.id, FrameButtonAction.button == button
-            )
-        )
-        for i, item in enumerate(body.actions):
-            db.add(FrameButtonAction(
-                frame_id=frame.id, button=button, widget_id=item.widget_id, action=item.action,
-                sort_order=i, created_at=time.time(),
-            ))
-        db.commit()
-    return {"status": "saved"}
-
-
 @router.get("/api/frames/{frame_id}/battery-log")
 def api_battery_log(frame: Frame = Depends(require_frame_view), db: Session = Depends(get_db)):
     rows = db.execute(