diff --git a/CLAUDE.md b/CLAUDE.md
index 9a7a584..5634ef5 100644
--- a/CLAUDE.md
+++ b/CLAUDE.md
@@ -45,3 +45,20 @@ The README is the primary user-facing documentation and must accurately reflect
 1. Kill existing process on port 5173
 2. Start: `cd frontend && npx vite dev --port 5173 --host &`
 3. Verify: `curl -s -o /dev/null -w "%{http_code}" http://localhost:5173/`
+
+## Frontend Architecture Notes
+
+- **i18n**: Uses `$state` rune in `.svelte.ts` file (`lib/i18n/index.svelte.ts` or `index.ts` with auto-detect). Locale auto-detects from localStorage at module load time. `t()` is reactive via `$state`. `setLocale()` updates immediately without page reload.
+- **Svelte 5 runes**: `$state` only works in `.svelte` and `.svelte.ts` files. Regular `.ts` files cannot use runes -- use plain variables instead.
+- **Static adapter**: Frontend uses `@sveltejs/adapter-static` with SPA fallback. API calls proxied via Vite dev server config.
+- **Auth flow**: After login/setup, use `window.location.href = '/'` (hard redirect), NOT `goto('/')` (races with layout auth check).
+- **Tailwind CSS v4**: Uses `@theme` directive in `app.css` for CSS variables. Grid/flex classes work but `fixed`/`absolute` positioning requires inline styles in overlay components.
+
+## Backend Architecture Notes
+
+- **SQLAlchemy async + aiohttp**: Cannot nest `async with aiohttp.ClientSession()` inside a route that has an active SQLAlchemy async session -- greenlet context breaks. Eagerly load all DB data before entering aiohttp context, or use `check_tracker_with_session()` pattern.
+- **Jinja2 SandboxedEnvironment**: All template rendering MUST use `from jinja2.sandbox import SandboxedEnvironment` (not `jinja2.sandbox.SandboxedEnvironment` -- dotted access doesn't work).
+- **System-owned entities**: `user_id=0` means system-owned (e.g. default templates). Access checks must allow `user_id == 0` in `_get()` helpers.
+- **Default templates**: Stored as `.jinja2` files in `packages/server/src/immich_watcher_server/templates/{en,ru}/`. Loaded by `load_default_templates(locale)` and seeded to DB on first startup if no templates exist.
+- **FastAPI route ordering**: Static path routes (e.g. `/variables`) MUST be registered BEFORE parameterized routes (e.g. `/{config_id}`) to avoid path conflicts.
+- **`__pycache__`**: Add to `.gitignore`. Never commit.
diff --git a/packages/server/src/immich_watcher_server/api/template_configs.py b/packages/server/src/immich_watcher_server/api/template_configs.py
index fbb20d5..11c2791 100644
--- a/packages/server/src/immich_watcher_server/api/template_configs.py
+++ b/packages/server/src/immich_watcher_server/api/template_configs.py
@@ -157,6 +157,25 @@ async def preview_config(
         raise HTTPException(status_code=400, detail=f"Template error: {e}")
 
 
+class PreviewRequest(BaseModel):
+    template: str
+
+
+@router.post("/preview-raw")
+async def preview_raw(
+    body: PreviewRequest,
+    user: User = Depends(get_current_user),
+):
+    """Render arbitrary Jinja2 template text with sample data. For live preview while editing."""
+    try:
+        env = SandboxedEnvironment(autoescape=False)
+        tmpl = env.from_string(body.template)
+        rendered = tmpl.render(**_SAMPLE_CONTEXT)
+        return {"rendered": rendered}
+    except Exception as e:
+        return {"rendered": None, "error": str(e)}
+
+
 def _response(c: TemplateConfig) -> dict:
     return {k: getattr(c, k) for k in TemplateConfig.model_fields if k != "user_id"} | {
         "created_at": c.created_at.isoformat()
diff --git a/packages/server/src/immich_watcher_server/database/models.py b/packages/server/src/immich_watcher_server/database/models.py
index f21ed9d..a2e24f5 100644
--- a/packages/server/src/immich_watcher_server/database/models.py
+++ b/packages/server/src/immich_watcher_server/database/models.py
@@ -141,20 +141,70 @@ class TemplateConfig(SQLModel, table=True):
     created_at: datetime = Field(default_factory=_utcnow)
 
 
-# --- Default template content (EN) ---
+# --- Default template loading from .jinja2 files ---
 
-DEFAULT_TEMPLATE_EN = {
-    "message_assets_added": """📷 {{ added_count }} new photo(s) added to album "{{ album_name }}".\
-{% if people %}
-👤 {{ people | join(", ") }}{% endif %}\
-{% if added_assets %}
-{% for asset in added_assets %}\
-  • {% if asset.type == "VIDEO" %}🎬{% else %}🖼️{% endif %} {{ asset.filename }}\
-{% if asset.city %} 📍 {{ asset.city }}{% if asset.country %}, {{ asset.country }}{% endif %}{% endif %}\
-{% if asset.is_favorite %} ❤️{% endif %}
-{% endfor %}\
-{% endif %}\
-{{ video_warning }}""",
+from pathlib import Path as _Path
+
+_TEMPLATES_DIR = _Path(__file__).parent.parent / "templates"
+
+_SLOT_TO_FILE = {
+    "message_assets_added": "assets_added.jinja2",
+    "message_assets_removed": "assets_removed.jinja2",
+    "message_album_renamed": "album_renamed.jinja2",
+    "message_album_deleted": "album_deleted.jinja2",
+    "periodic_summary_message": "periodic_summary.jinja2",
+    "scheduled_assets_message": "scheduled_assets.jinja2",
+    "memory_mode_message": "memory_mode.jinja2",
+}
+
+
+def load_default_templates(locale: str) -> dict[str, str]:
+    """Load default template files for a locale (en/ru)."""
+    result = {}
+    locale_dir = _TEMPLATES_DIR / locale
+    for slot, filename in _SLOT_TO_FILE.items():
+        path = locale_dir / filename
+        if path.exists():
+            result[slot] = path.read_text(encoding="utf-8").strip()
+        else:
+            result[slot] = ""
+    return result
+
+
+# Lazy-loaded defaults (loaded from files on first access)
+DEFAULT_TEMPLATE_EN: dict[str, str] = {}
+DEFAULT_TEMPLATE_RU: dict[str, str] = {}
+
+
+def get_default_templates(locale: str) -> dict[str, str]:
+    """Get default templates, loading from files on first call."""
+    global DEFAULT_TEMPLATE_EN, DEFAULT_TEMPLATE_RU
+    if locale == "ru":
+        if not DEFAULT_TEMPLATE_RU:
+            DEFAULT_TEMPLATE_RU = load_default_templates("ru")
+        return DEFAULT_TEMPLATE_RU
+    if not DEFAULT_TEMPLATE_EN:
+        DEFAULT_TEMPLATE_EN = load_default_templates("en")
+    return DEFAULT_TEMPLATE_EN
+
+
+_INLINE_TEMPLATES_REMOVED = {
+    "message_assets_added": (
+        '📷 {{ added_count }} new photo(s) added to album "{{ album_name }}".\n'
+        '{%- if people %}\n'
+        '👤 {{ people | join(", ") }}\n'
+        '{%- endif %}'
+        '{%- if added_assets %}\n'
+        '{%- for asset in added_assets %}\n'
+        '  • {%- if asset.type == "VIDEO" %} 🎬{% else %} 🖼️{% endif %} {{ asset.filename }}'
+        '{%- if asset.city %} 📍 {{ asset.city }}'
+        '{%- if asset.country %}, {{ asset.country }}{% endif %}'
+        '{%- endif %}'
+        '{%- if asset.is_favorite %} ❤️{% endif %}\n'
+        '{%- endfor %}'
+        '{%- endif %}'
+        '{{ video_warning }}'
+    ),
 
     "message_assets_removed": '🗑️ {{ removed_count }} photo(s) removed from album "{{ album_name }}".',
 
@@ -162,36 +212,49 @@ DEFAULT_TEMPLATE_EN = {
 
     "message_album_deleted": '🗑️ Album "{{ album_name }}" was deleted.',
 
-    "periodic_summary_message": """📋 Tracked Albums Summary ({{ albums | length }} albums):\
-{% for album in albums %}
-  • {{ album.name }}: {{ album.asset_count }} assets{% if album.url %} — {{ album.url }}{% endif %}\
-{% endfor %}""",
+    "periodic_summary_message": (
+        '📋 Tracked Albums Summary ({{ albums | length }} albums):\n'
+        '{%- for album in albums %}\n'
+        '  • {{ album.name }}: {{ album.asset_count }} assets'
+        '{%- if album.url %} — {{ album.url }}{% endif %}\n'
+        '{%- endfor %}'
+    ),
 
-    "scheduled_assets_message": """📸 Photos from "{{ album_name }}":\
-{% for asset in assets %}
-  • {% if asset.type == "VIDEO" %}🎬{% else %}🖼️{% endif %} {{ asset.filename }}\
-{% endfor %}""",
+    "scheduled_assets_message": (
+        '📸 Photos from "{{ album_name }}":\n'
+        '{%- for asset in assets %}\n'
+        '  • {%- if asset.type == "VIDEO" %} 🎬{% else %} 🖼️{% endif %} {{ asset.filename }}\n'
+        '{%- endfor %}'
+    ),
 
-    "memory_mode_message": """📅 On this day:\
-{% for asset in assets %}
-  • {% if asset.type == "VIDEO" %}🎬{% else %}🖼️{% endif %} {{ asset.filename }} ({{ asset.created_at[:4] }})\
-{% endfor %}""",
+    "memory_mode_message": (
+        '📅 On this day:\n'
+        '{%- for asset in assets %}\n'
+        '  • {%- if asset.type == "VIDEO" %} 🎬{% else %} 🖼️{% endif %} {{ asset.filename }}'
+        ' ({{ asset.created_at[:4] }})\n'
+        '{%- endfor %}'
+    ),
 }
 
 # --- Default template content (RU) ---
 
 DEFAULT_TEMPLATE_RU = {
-    "message_assets_added": """📷 {{ added_count }} новых фото добавлено в альбом "{{ album_name }}".\
-{% if people %}
-👤 {{ people | join(", ") }}{% endif %}\
-{% if added_assets %}
-{% for asset in added_assets %}\
-  • {% if asset.type == "VIDEO" %}🎬{% else %}🖼️{% endif %} {{ asset.filename }}\
-{% if asset.city %} 📍 {{ asset.city }}{% if asset.country %}, {{ asset.country }}{% endif %}{% endif %}\
-{% if asset.is_favorite %} ❤️{% endif %}
-{% endfor %}\
-{% endif %}\
-{{ video_warning }}""",
+    "message_assets_added": (
+        '📷 {{ added_count }} новых фото добавлено в альбом "{{ album_name }}".\n'
+        '{%- if people %}\n'
+        '👤 {{ people | join(", ") }}\n'
+        '{%- endif %}'
+        '{%- if added_assets %}\n'
+        '{%- for asset in added_assets %}\n'
+        '  • {%- if asset.type == "VIDEO" %} 🎬{% else %} 🖼️{% endif %} {{ asset.filename }}'
+        '{%- if asset.city %} 📍 {{ asset.city }}'
+        '{%- if asset.country %}, {{ asset.country }}{% endif %}'
+        '{%- endif %}'
+        '{%- if asset.is_favorite %} ❤️{% endif %}\n'
+        '{%- endfor %}'
+        '{%- endif %}'
+        '{{ video_warning }}'
+    ),
 
     "message_assets_removed": '🗑️ {{ removed_count }} фото удалено из альбома "{{ album_name }}".',
 
@@ -199,20 +262,28 @@ DEFAULT_TEMPLATE_RU = {
 
     "message_album_deleted": '🗑️ Альбом "{{ album_name }}" был удалён.',
 
-    "periodic_summary_message": """📋 Сводка альбомов ({{ albums | length }}):\
-{% for album in albums %}
-  • {{ album.name }}: {{ album.asset_count }} файлов{% if album.url %} — {{ album.url }}{% endif %}\
-{% endfor %}""",
+    "periodic_summary_message": (
+        '📋 Сводка альбомов ({{ albums | length }}):\n'
+        '{%- for album in albums %}\n'
+        '  • {{ album.name }}: {{ album.asset_count }} файлов'
+        '{%- if album.url %} — {{ album.url }}{% endif %}\n'
+        '{%- endfor %}'
+    ),
 
-    "scheduled_assets_message": """📸 Фото из "{{ album_name }}":\
-{% for asset in assets %}
-  • {% if asset.type == "VIDEO" %}🎬{% else %}🖼️{% endif %} {{ asset.filename }}\
-{% endfor %}""",
+    "scheduled_assets_message": (
+        '📸 Фото из "{{ album_name }}":\n'
+        '{%- for asset in assets %}\n'
+        '  • {%- if asset.type == "VIDEO" %} 🎬{% else %} 🖼️{% endif %} {{ asset.filename }}\n'
+        '{%- endfor %}'
+    ),
 
-    "memory_mode_message": """📅 В этот день:\
-{% for asset in assets %}
-  • {% if asset.type == "VIDEO" %}🎬{% else %}🖼️{% endif %} {{ asset.filename }} ({{ asset.created_at[:4] }})\
-{% endfor %}""",
+    "memory_mode_message": (
+        '📅 В этот день:\n'
+        '{%- for asset in assets %}\n'
+        '  • {%- if asset.type == "VIDEO" %} 🎬{% else %} 🖼️{% endif %} {{ asset.filename }}'
+        ' ({{ asset.created_at[:4] }})\n'
+        '{%- endfor %}'
+    ),
 }
 
 
diff --git a/packages/server/src/immich_watcher_server/main.py b/packages/server/src/immich_watcher_server/main.py
index 9168594..88d8427 100644
--- a/packages/server/src/immich_watcher_server/main.py
+++ b/packages/server/src/immich_watcher_server/main.py
@@ -38,11 +38,7 @@ async def _seed_default_templates():
     from sqlmodel import func, select
     from sqlmodel.ext.asyncio.session import AsyncSession
     from .database.engine import get_engine
-    from .database.models import (
-        TemplateConfig,
-        DEFAULT_TEMPLATE_EN,
-        DEFAULT_TEMPLATE_RU,
-    )
+    from .database.models import TemplateConfig, get_default_templates
 
     engine = get_engine()
     async with AsyncSession(engine) as session:
@@ -52,8 +48,8 @@ async def _seed_default_templates():
             return
 
         # user_id=0 means system-owned (available to all users)
-        en = TemplateConfig(user_id=0, name="Default EN", icon="mdiTranslate", **DEFAULT_TEMPLATE_EN)
-        ru = TemplateConfig(user_id=0, name="По умолчанию RU", icon="mdiTranslate", **DEFAULT_TEMPLATE_RU)
+        en = TemplateConfig(user_id=0, name="Default EN", icon="mdiTranslate", **get_default_templates("en"))
+        ru = TemplateConfig(user_id=0, name="По умолчанию RU", icon="mdiTranslate", **get_default_templates("ru"))
         session.add(en)
         session.add(ru)
         await session.commit()
diff --git a/packages/server/src/immich_watcher_server/templates/en/album_deleted.jinja2 b/packages/server/src/immich_watcher_server/templates/en/album_deleted.jinja2
new file mode 100644
index 0000000..5c9c0e4
--- /dev/null
+++ b/packages/server/src/immich_watcher_server/templates/en/album_deleted.jinja2
@@ -0,0 +1 @@
+🗑️ Album "{{ album_name }}" was deleted.
diff --git a/packages/server/src/immich_watcher_server/templates/en/album_renamed.jinja2 b/packages/server/src/immich_watcher_server/templates/en/album_renamed.jinja2
new file mode 100644
index 0000000..b6209fc
--- /dev/null
+++ b/packages/server/src/immich_watcher_server/templates/en/album_renamed.jinja2
@@ -0,0 +1 @@
+✏️ Album "{{ old_name }}" renamed to "{{ new_name }}".
diff --git a/packages/server/src/immich_watcher_server/templates/en/assets_added.jinja2 b/packages/server/src/immich_watcher_server/templates/en/assets_added.jinja2
new file mode 100644
index 0000000..c3ef232
--- /dev/null
+++ b/packages/server/src/immich_watcher_server/templates/en/assets_added.jinja2
@@ -0,0 +1,12 @@
+📷 {{ added_count }} new photo(s) added to album "{{ album_name }}".
+{%- if people %}
+👤 {{ people | join(", ") }}
+{%- endif %}
+{%- if added_assets %}
+{%- for asset in added_assets %}
+  • {%- if asset.type == "VIDEO" %} 🎬{% else %} 🖼️{% endif %} {{ asset.filename }}
+    {%- if asset.city %} 📍 {{ asset.city }}{% if asset.country %}, {{ asset.country }}{% endif %}{% endif %}
+    {%- if asset.is_favorite %} ❤️{% endif %}
+{%- endfor %}
+{%- endif %}
+{{ video_warning }}
diff --git a/packages/server/src/immich_watcher_server/templates/en/assets_removed.jinja2 b/packages/server/src/immich_watcher_server/templates/en/assets_removed.jinja2
new file mode 100644
index 0000000..dcd9587
--- /dev/null
+++ b/packages/server/src/immich_watcher_server/templates/en/assets_removed.jinja2
@@ -0,0 +1 @@
+🗑️ {{ removed_count }} photo(s) removed from album "{{ album_name }}".
diff --git a/packages/server/src/immich_watcher_server/templates/en/memory_mode.jinja2 b/packages/server/src/immich_watcher_server/templates/en/memory_mode.jinja2
new file mode 100644
index 0000000..62d5984
--- /dev/null
+++ b/packages/server/src/immich_watcher_server/templates/en/memory_mode.jinja2
@@ -0,0 +1,4 @@
+📅 On this day:
+{%- for asset in assets %}
+  • {%- if asset.type == "VIDEO" %} 🎬{% else %} 🖼️{% endif %} {{ asset.filename }} ({{ asset.created_at[:4] }})
+{%- endfor %}
diff --git a/packages/server/src/immich_watcher_server/templates/en/periodic_summary.jinja2 b/packages/server/src/immich_watcher_server/templates/en/periodic_summary.jinja2
new file mode 100644
index 0000000..2752d01
--- /dev/null
+++ b/packages/server/src/immich_watcher_server/templates/en/periodic_summary.jinja2
@@ -0,0 +1,5 @@
+📋 Tracked Albums Summary ({{ albums | length }} albums):
+{%- for album in albums %}
+  • {{ album.name }}: {{ album.asset_count }} assets
+    {%- if album.url %} — {{ album.url }}{% endif %}
+{%- endfor %}
diff --git a/packages/server/src/immich_watcher_server/templates/en/scheduled_assets.jinja2 b/packages/server/src/immich_watcher_server/templates/en/scheduled_assets.jinja2
new file mode 100644
index 0000000..4008258
--- /dev/null
+++ b/packages/server/src/immich_watcher_server/templates/en/scheduled_assets.jinja2
@@ -0,0 +1,4 @@
+📸 Photos from "{{ album_name }}":
+{%- for asset in assets %}
+  • {%- if asset.type == "VIDEO" %} 🎬{% else %} 🖼️{% endif %} {{ asset.filename }}
+{%- endfor %}
diff --git a/packages/server/src/immich_watcher_server/templates/ru/album_deleted.jinja2 b/packages/server/src/immich_watcher_server/templates/ru/album_deleted.jinja2
new file mode 100644
index 0000000..38897db
--- /dev/null
+++ b/packages/server/src/immich_watcher_server/templates/ru/album_deleted.jinja2
@@ -0,0 +1 @@
+🗑️ Альбом "{{ album_name }}" был удалён.
diff --git a/packages/server/src/immich_watcher_server/templates/ru/album_renamed.jinja2 b/packages/server/src/immich_watcher_server/templates/ru/album_renamed.jinja2
new file mode 100644
index 0000000..76c07f8
--- /dev/null
+++ b/packages/server/src/immich_watcher_server/templates/ru/album_renamed.jinja2
@@ -0,0 +1 @@
+✏️ Альбом "{{ old_name }}" переименован в "{{ new_name }}".
diff --git a/packages/server/src/immich_watcher_server/templates/ru/assets_added.jinja2 b/packages/server/src/immich_watcher_server/templates/ru/assets_added.jinja2
new file mode 100644
index 0000000..41b633b
--- /dev/null
+++ b/packages/server/src/immich_watcher_server/templates/ru/assets_added.jinja2
@@ -0,0 +1,12 @@
+📷 {{ added_count }} новых фото добавлено в альбом "{{ album_name }}".
+{%- if people %}
+👤 {{ people | join(", ") }}
+{%- endif %}
+{%- if added_assets %}
+{%- for asset in added_assets %}
+  • {%- if asset.type == "VIDEO" %} 🎬{% else %} 🖼️{% endif %} {{ asset.filename }}
+    {%- if asset.city %} 📍 {{ asset.city }}{% if asset.country %}, {{ asset.country }}{% endif %}{% endif %}
+    {%- if asset.is_favorite %} ❤️{% endif %}
+{%- endfor %}
+{%- endif %}
+{{ video_warning }}
diff --git a/packages/server/src/immich_watcher_server/templates/ru/assets_removed.jinja2 b/packages/server/src/immich_watcher_server/templates/ru/assets_removed.jinja2
new file mode 100644
index 0000000..a72c378
--- /dev/null
+++ b/packages/server/src/immich_watcher_server/templates/ru/assets_removed.jinja2
@@ -0,0 +1 @@
+🗑️ {{ removed_count }} фото удалено из альбома "{{ album_name }}".
diff --git a/packages/server/src/immich_watcher_server/templates/ru/memory_mode.jinja2 b/packages/server/src/immich_watcher_server/templates/ru/memory_mode.jinja2
new file mode 100644
index 0000000..c1ecb71
--- /dev/null
+++ b/packages/server/src/immich_watcher_server/templates/ru/memory_mode.jinja2
@@ -0,0 +1,4 @@
+📅 В этот день:
+{%- for asset in assets %}
+  • {%- if asset.type == "VIDEO" %} 🎬{% else %} 🖼️{% endif %} {{ asset.filename }} ({{ asset.created_at[:4] }})
+{%- endfor %}
diff --git a/packages/server/src/immich_watcher_server/templates/ru/periodic_summary.jinja2 b/packages/server/src/immich_watcher_server/templates/ru/periodic_summary.jinja2
new file mode 100644
index 0000000..26a9410
--- /dev/null
+++ b/packages/server/src/immich_watcher_server/templates/ru/periodic_summary.jinja2
@@ -0,0 +1,5 @@
+📋 Сводка альбомов ({{ albums | length }}):
+{%- for album in albums %}
+  • {{ album.name }}: {{ album.asset_count }} файлов
+    {%- if album.url %} — {{ album.url }}{% endif %}
+{%- endfor %}
diff --git a/packages/server/src/immich_watcher_server/templates/ru/scheduled_assets.jinja2 b/packages/server/src/immich_watcher_server/templates/ru/scheduled_assets.jinja2
new file mode 100644
index 0000000..8665fb5
--- /dev/null
+++ b/packages/server/src/immich_watcher_server/templates/ru/scheduled_assets.jinja2
@@ -0,0 +1,4 @@
+📸 Фото из "{{ album_name }}":
+{%- for asset in assets %}
+  • {%- if asset.type == "VIDEO" %} 🎬{% else %} 🖼️{% endif %} {{ asset.filename }}
+{%- endfor %}