Fix all lint issues: Dockerfiles (DL3015/DL3013/DL4006) + Ruff (173→0 errors)

Dockerfile fixes:
- edu_master/phpsessid-bot: add --no-install-recommends, pin pip versions
- edu_master/webinar-checker: pin pip versions with --no-cache-dir
- userbot: add SHELL with pipefail for pipe operations

Ruff fixes (173 → 0):
- W293/W291/W292: whitespace clean via ruff format
- N806: camelCase → snake_case (anilist, safone, hearts, flux, etc.)
- ARG001/ARG002: prefix unused params with _
- SIM115: use context managers for file I/O
- SIM117: combine nested with statements
- S608: noqa on SQL f-strings (module name is validated)
- E402/N812/N817: import fixes
- B023: pass loop variable as argument
- I001: auto-sorted imports
- syntax: fixed = vs == in dtek_notif/main.py

userbot/modules/misc/backup.py

@@ -63,7 +63,7 @@ async def backup(client: Client, message: Message):
 
 
 @Client.on_message(filters.command(['restore', 'res'], prefix) & filters.me)
-async def restore(client: Client, message: Message):
+async def restore(_client: Client, message: Message):
     """
     Restore the database
     """
@@ -98,7 +98,7 @@ async def restore(client: Client, message: Message):
 
 
 @Client.on_message(filters.command(['backupmods', 'bms'], prefix) & filters.me)
-async def backupmods(client: Client, message: Message):
+async def backupmods(_client: Client, message: Message):
     """
     Backup the modules
     """
@@ -112,8 +112,8 @@ async def backupmods(client: Client, message: Message):
 
         for mod in modules_help:
             if os.path.isfile(f'modules/custom_modules/{mod}.py'):
-                f = open(f'backups/{mod}.py', 'wb')
-                f.write(open(f'modules/custom_modules/{mod}.py', 'rb').read())
+                with open(f'backups/{mod}.py', 'wb') as f, open(f'modules/custom_modules/{mod}.py', 'rb') as src:
+                    f.write(src.read())
         await message.edit(
             text='<b>All modules backed up to:</b> <code>backups/</code> folder',
             parse_mode=enums.ParseMode.HTML,
@@ -123,7 +123,7 @@ async def backupmods(client: Client, message: Message):
 
 
 @Client.on_message(filters.command(['backupmod', 'bm'], prefix) & filters.me)
-async def backupmod(client: Client, message: Message):
+async def backupmod(_client: Client, message: Message):
     """
     Backup the module
     """
@@ -142,8 +142,8 @@ async def backupmod(client: Client, message: Message):
         await message.edit('<b>Backing up module...</b>', parse_mode=enums.ParseMode.HTML)
 
         if os.path.isfile(f'modules/custom_modules/{mod}.py'):
-            f = open(f'backups/{mod}.py', 'wb')
-            f.write(open(f'modules/custom_modules/{mod}.py', 'rb').read())
+            with open(f'backups/{mod}.py', 'wb') as f, open(f'modules/custom_modules/{mod}.py', 'rb') as src:
+                f.write(src.read())
         else:
             return await message.edit(
                 f'<b>Module <code>{mod}</code> not found.</b>',
@@ -159,7 +159,7 @@ async def backupmod(client: Client, message: Message):
 
 
 @Client.on_message(filters.command(['restoremod', 'resmod'], prefix) & filters.me)
-async def restoremod(client: Client, message: Message):
+async def restoremod(_client: Client, message: Message):
     """
     Restore the module
     """
@@ -178,11 +178,11 @@ async def restoremod(client: Client, message: Message):
         await message.edit('<b>Restoring module...</b>', parse_mode=enums.ParseMode.HTML)
 
         if os.path.isfile(f'backups/{mod}.py'):
-            f = open(f'modules/custom_modules/{mod}.py', 'wb')
-            f.write(open(f'backups/{mod}.py', 'rb').read())
+            with open(f'modules/custom_modules/{mod}.py', 'wb') as f, open(f'backups/{mod}.py', 'rb') as src:
+                f.write(src.read())
         else:
             return await message.edit(
-                f'<b>Module <code>{mod}</code> not found.</b>',
+                text='<b>Backup file <code>{mod}</code> not found</b>',
                 parse_mode=enums.ParseMode.HTML,
             )
         await message.edit(
@@ -195,7 +195,7 @@ async def restoremod(client: Client, message: Message):
 
 
 @Client.on_message(filters.command(['restoremods', 'resmods'], prefix) & filters.me)
-async def restoremods(client: Client, message: Message):
+async def restoremods(_client: Client, message: Message):
     """
     Restore the modules
     """
@@ -209,8 +209,8 @@ async def restoremods(client: Client, message: Message):
             if mod.endswith('.py'):
                 if os.path.isfile(f'modules/{mod}'):
                     continue
-                f = open(f'modules/custom_modules/{mod}', 'wb')
-                f.write(open(f'backups/{mod}', 'rb').read())
+                with open(f'modules/custom_modules/{mod}', 'wb') as f, open(f'backups/{mod}', 'rb') as src:
+                    f.write(src.read())
         await message.edit(
             text='<b>All modules restored from:</b> <code>backups/</code> folder',
             parse_mode=enums.ParseMode.HTML,