feat(recipes): add recently opened sort with modal open tracking

Track recipe modal opens in a separate stats file (never touching recipe
JSON/EXIF), expose a fire-and-forget POST endpoint, and add an 'opened'
sort that hides never-opened recipes as a true recently-opened view.
Includes i18n for all locales and backend/frontend tests.

py/routes/handlers/recipe_handlers.py

@@ -34,6 +34,7 @@ from ...utils.civitai_utils import (
 )
 from ...utils.constants import NSFW_LEVELS
 from ...utils.exif_utils import ExifUtils
+from ...utils.recipe_open_stats import RecipeOpenStats
 from ...recipes.merger import GenParamsMerger
 from ...recipes.enrichment import RecipeEnricher
 from ...services.websocket_manager import ws_manager as default_ws_manager
@@ -98,6 +99,7 @@ class RecipeHandlerSet:
             "download_shared_recipe": self.sharing.download_shared_recipe,
             "get_recipe_syntax": self.query.get_recipe_syntax,
             "update_recipe": self.management.update_recipe,
+            "record_recipe_open": self.management.record_recipe_open,
             "reconnect_lora": self.management.reconnect_lora,
             "find_duplicates": self.query.find_duplicates,
             "move_recipes_bulk": self.management.move_recipes_bulk,
@@ -1458,6 +1460,33 @@ class RecipeManagementHandler:
             self._logger.error("Error updating recipe: %s", exc, exc_info=True)
             return web.json_response({"error": str(exc)}, status=500)
 
+    async def record_recipe_open(self, request: web.Request) -> web.Response:
+        """Record that a recipe's detail modal was opened.
+
+        Lightweight fire-and-forget endpoint backing the "Recently Opened"
+        sort. It only writes the timestamp into the separate open-stats file
+        — recipe JSON and EXIF are never touched.
+        """
+        try:
+            await self._ensure_dependencies_ready()
+            recipe_scanner = self._recipe_scanner_getter()
+            if recipe_scanner is None:
+                raise RuntimeError("Recipe scanner unavailable")
+
+            recipe_id = request.match_info["recipe_id"]
+            # Skip recording opens for recipes the scanner no longer knows.
+            recipe_json_path = await recipe_scanner.get_recipe_json_path(recipe_id)
+            if not recipe_json_path:
+                return web.json_response(
+                    {"success": False, "error": "Recipe not found"}, status=404
+                )
+
+            RecipeOpenStats().record_open(recipe_id)
+            return web.json_response({"success": True})
+        except Exception as exc:
+            self._logger.error("Error recording recipe open: %s", exc, exc_info=True)
+            return web.json_response({"success": False, "error": str(exc)}, status=500)
+
     async def move_recipe(self, request: web.Request) -> web.Response:
         try:
             await self._ensure_dependencies_ready()

py/routes/recipe_route_registrar.py

@@ -43,6 +43,9 @@ ROUTE_DEFINITIONS: tuple[RouteDefinition, ...] = (
     ),
     RouteDefinition("GET", "/api/lm/recipe/{recipe_id}/syntax", "get_recipe_syntax"),
     RouteDefinition("PUT", "/api/lm/recipe/{recipe_id}/update", "update_recipe"),
+    RouteDefinition(
+        "POST", "/api/lm/recipe/{recipe_id}/opened", "record_recipe_open"
+    ),
     RouteDefinition("POST", "/api/lm/recipe/move", "move_recipe"),
     RouteDefinition("POST", "/api/lm/recipes/move-bulk", "move_recipes_bulk"),
     RouteDefinition("POST", "/api/lm/recipe/lora/reconnect", "reconnect_lora"),

py/services/recipe_scanner.py

@@ -14,6 +14,7 @@ from typing import Any, Callable, Dict, Iterable, List, Optional, Set, Tuple, Un
 from ..config import config
 from ..utils.constants import VALID_CHECKPOINT_SUB_TYPES, VALID_LORA_TYPES
 from ..utils.file_utils import calculate_autov3
+from ..utils.recipe_open_stats import RecipeOpenStats
 from .recipe_cache import RecipeCache
 from .recipes.errors import RecipeNotFoundError, RecipePersistenceError
 from natsort import natsorted
@@ -2782,9 +2783,11 @@ class RecipeScanner:
         Args:
             page: Current page number (1-based)
             page_size: Number of items per page
-            sort_by: Sort method ('name', 'date', 'loras_count', or 'random'
-                with an optional seed like 'random:abc123'; the part after
-                'random:' is the shuffle seed, not a direction)
+            sort_by: Sort method ('name', 'date', 'loras_count', 'opened',
+                or 'random' with an optional seed like 'random:abc123'; the
+                part after 'random:' is the shuffle seed, not a direction).
+                'opened' hides recipes that were never opened — it is a
+                "recently opened" view, not a plain reorder
             search: Search term
             filters: Dictionary of filters to apply
             search_options: Dictionary of search options to apply
@@ -2965,7 +2968,7 @@ class RecipeScanner:
                         ]
 
         # Apply sorting if not already handled by pre-sorted cache
-        if ":" in sort_by or sort_field in ("loras_count", "random"):
+        if ":" in sort_by or sort_field in ("loras_count", "random", "opened"):
             field, order = (sort_by.split(":") + ["desc"])[:2]
             reverse = order.lower() == "desc"
 
@@ -2984,6 +2987,20 @@ class RecipeScanner:
                     ),
                     reverse=reverse,
                 )
+            elif field == "opened":
+                # "Recently Opened" view: recipes never opened are hidden.
+                # The open stats live outside recipe metadata; see
+                # RecipeOpenStats.
+                opened_map = RecipeOpenStats().get_opened_map()
+                filtered_data = [
+                    item
+                    for item in filtered_data
+                    if opened_map.get(str(item.get("id", ""))) is not None
+                ]
+                filtered_data.sort(
+                    key=lambda x: opened_map.get(str(x.get("id", "")), 0),
+                    reverse=reverse,
+                )
             elif field == "loras_count":
                 filtered_data.sort(
                     key=lambda x: len(x.get("loras", [])), reverse=reverse

py/utils/recipe_open_stats.py

@@ -0,0 +1,161 @@
+"""Track recipe modal open timestamps for the "Recently Opened" sort.
+
+The data is deliberately kept OUTSIDE the recipe metadata files: recording an
+open must be cheap and must never rewrite recipe JSON or EXIF (which the
+generic metadata update path does). A tiny JSON map of
+``recipe_id -> unix timestamp`` lives under
+``{settings_dir}/stats/recipe_last_opened.json`` and is written atomically on
+a short debounce.
+"""
+
+from __future__ import annotations
+
+import asyncio
+import json
+import logging
+import os
+import time
+
+from ..utils.settings_paths import get_settings_dir
+
+logger = logging.getLogger(__name__)
+
+
+class RecipeOpenStats:
+    """Persist the last time each recipe was opened in the recipe modal."""
+
+    STATS_FILENAME: str = "recipe_last_opened.json"
+    SAVE_DELAY: float = 1.0  # seconds of debounce between consecutive writes
+
+    _instance: "RecipeOpenStats | None" = None
+    _opened: dict[str, float]
+    _file_mtime: float | None
+    _dirty: bool
+    _lock: asyncio.Lock
+    _save_task: "asyncio.Task[None] | None"
+    _stats_file_path: str
+    _initialized: bool
+
+    def __new__(cls) -> "RecipeOpenStats":
+        if cls._instance is None:
+            cls._instance = super().__new__(cls)
+            cls._instance._initialized = False
+        return cls._instance
+
+    def __init__(self) -> None:
+        if getattr(self, "_initialized", False):
+            return
+        self._opened = {}
+        self._file_mtime = None
+        self._dirty = False
+        self._lock = asyncio.Lock()
+        self._save_task = None
+        self._stats_file_path = self._get_stats_file_path()
+        self._load_stats()
+        self._initialized = True
+
+    def _get_stats_file_path(self) -> str:
+        settings_dir = get_settings_dir(create=True)
+        return os.path.join(settings_dir, "stats", self.STATS_FILENAME)
+
+    def _load_stats(self) -> None:
+        """Load the opened map from disk, tolerating corrupt/absent files.
+
+        The mtime is recorded even when parsing fails so a corrupt file is
+        not re-read (and re-logged) on every lookup.
+        """
+        if not os.path.exists(self._stats_file_path):
+            return
+        try:
+            mtime = os.path.getmtime(self._stats_file_path)
+        except OSError:
+            return
+        try:
+            with open(self._stats_file_path, "r", encoding="utf-8") as file_obj:
+                raw = json.load(file_obj)
+            if isinstance(raw, dict):
+                self._opened = {
+                    str(key): float(value)
+                    for key, value in raw.items()
+                    if isinstance(value, (int, float))
+                }
+        except Exception as exc:  # pragma: no cover - defensive logging path
+            logger.error("Error loading recipe open stats: %s", exc)
+            self._opened = {}
+        self._file_mtime = mtime
+
+    def get_opened_map(self) -> dict[str, float]:
+        """Return a copy of ``recipe_id -> last opened timestamp``.
+
+        Refreshes from disk when the file changed since the last load so a
+        second server process (or manual edit) is picked up without restart.
+        """
+        try:
+            if os.path.exists(self._stats_file_path):
+                mtime = os.path.getmtime(self._stats_file_path)
+                if self._file_mtime is None or mtime != self._file_mtime:
+                    self._load_stats()
+        except OSError:
+            pass
+        return dict(self._opened)
+
+    def record_open(self, recipe_id: str) -> None:
+        """Mark a recipe as opened now; persists shortly in the background."""
+        if not recipe_id:
+            return
+        self._opened[str(recipe_id)] = time.time()
+        self._dirty = True
+        if self._save_task is None or self._save_task.done():
+            self._save_task = asyncio.create_task(self._delayed_save())
+
+    async def _delayed_save(self) -> None:
+        """Debounced writer: batches rapid consecutive opens into one write."""
+        await asyncio.sleep(self.SAVE_DELAY)
+        _ = await self.save_stats()
+
+    async def save_stats(self, force: bool = False) -> bool:
+        """Persist the opened map atomically if dirty (or when forced).
+
+        The on-disk map is merged in first so a second process sharing the
+        settings dir does not lose its entries; the larger timestamp wins
+        per recipe.
+        """
+        if not force and not self._dirty:
+            return False
+        async with self._lock:
+            if not force and not self._dirty:
+                return False
+            try:
+                merged = self._merge_with_disk()
+                os.makedirs(os.path.dirname(self._stats_file_path), exist_ok=True)
+                temp_path = f"{self._stats_file_path}.tmp"
+                with open(temp_path, "w", encoding="utf-8") as file_obj:
+                    json.dump(merged, file_obj, indent=2)
+                os.replace(temp_path, self._stats_file_path)
+                self._opened = merged
+                self._file_mtime = os.path.getmtime(self._stats_file_path)
+                self._dirty = False
+                return True
+            except Exception as exc:  # pragma: no cover - defensive logging path
+                logger.error("Error saving recipe open stats: %s", exc, exc_info=True)
+                return False
+
+    def _merge_with_disk(self) -> dict[str, float]:
+        """Merge the in-memory map with the current on-disk map."""
+        disk: dict[str, float] = {}
+        try:
+            if os.path.exists(self._stats_file_path):
+                with open(self._stats_file_path, "r", encoding="utf-8") as file_obj:
+                    raw = json.load(file_obj)
+                if isinstance(raw, dict):
+                    disk = {
+                        str(key): float(value)
+                        for key, value in raw.items()
+                        if isinstance(value, (int, float))
+                    }
+        except Exception as exc:  # pragma: no cover - defensive logging path
+            logger.error("Error reading recipe open stats for merge: %s", exc)
+        merged = dict(disk)
+        for key, value in self._opened.items():
+            merged[key] = max(value, disk.get(key, 0.0))
+        return merged