feat(phase1): add image storage utilities

- Create backend/services/image_storage.py with 4 core functions:
  - sanitize_filename(): remove unsafe chars, limit to 255 chars, convert to lowercase
  - get_unique_filename(): handle collisions with UUID suffix (format: {name}_{uuid8}_{variant}.jpg)
  - ensure_image_directories(): create /images/ root and category subdirs on startup
  - save_image(): save bytes to /images/{category}/{filename}, returns relative path
- Create comprehensive test suite (22 tests) covering all functionality
- Integrate ensure_image_directories() into FastAPI startup event
- Directory structure: /images/{category}/{filename}
- Collision handling: auto-suffix with UUID if filename exists
- All tests passing, pathlib.Path for safe operations

venv/lib/python3.12/site-packages/pygments/lexers/other.py

@@ -0,0 +1,41 @@
+"""
+    pygments.lexers.other
+    ~~~~~~~~~~~~~~~~~~~~~
+
+    Just export lexer classes previously contained in this module.
+
+    :copyright: Copyright 2006-present by the Pygments team, see AUTHORS.
+    :license: BSD, see LICENSE for details.
+"""
+
+# ruff: noqa: F401
+from pygments.lexers.sql import SqlLexer, MySqlLexer, SqliteConsoleLexer
+from pygments.lexers.shell import BashLexer, BashSessionLexer, BatchLexer, \
+    TcshLexer
+from pygments.lexers.robotframework import RobotFrameworkLexer
+from pygments.lexers.testing import GherkinLexer
+from pygments.lexers.esoteric import BrainfuckLexer, BefungeLexer, RedcodeLexer
+from pygments.lexers.prolog import LogtalkLexer
+from pygments.lexers.snobol import SnobolLexer
+from pygments.lexers.rebol import RebolLexer
+from pygments.lexers.configs import KconfigLexer, Cfengine3Lexer
+from pygments.lexers.modeling import ModelicaLexer
+from pygments.lexers.scripting import AppleScriptLexer, MOOCodeLexer, \
+    HybrisLexer
+from pygments.lexers.graphics import PostScriptLexer, GnuplotLexer, \
+    AsymptoteLexer, PovrayLexer
+from pygments.lexers.business import ABAPLexer, OpenEdgeLexer, \
+    GoodDataCLLexer, MaqlLexer
+from pygments.lexers.automation import AutoItLexer, AutohotkeyLexer
+from pygments.lexers.dsls import ProtoBufLexer, BroLexer, PuppetLexer, \
+    MscgenLexer, VGLLexer
+from pygments.lexers.basic import CbmBasicV2Lexer
+from pygments.lexers.pawn import SourcePawnLexer, PawnLexer
+from pygments.lexers.ecl import ECLLexer
+from pygments.lexers.urbi import UrbiscriptLexer
+from pygments.lexers.smalltalk import SmalltalkLexer, NewspeakLexer
+from pygments.lexers.installers import NSISLexer, RPMSpecLexer
+from pygments.lexers.textedit import AwkLexer
+from pygments.lexers.smv import NuSMVLexer
+
+__all__ = []