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/styles/coffee.py

@@ -0,0 +1,80 @@
+"""
+    pygments.styles.coffee
+    ~~~~~~~~~~~~~~~~~~~~~~
+
+    A warm and cozy theme based off gruvbox
+
+    :copyright: Copyright 2006-present by the Pygments team, see AUTHORS.
+    :license: BSD, see LICENSE for details.
+"""
+
+from pygments.style import Style
+from pygments.token import (Comment, Error, Generic, Keyword, Literal, Name,
+                            Number, Operator, Punctuation, String, Token)
+
+__all__ = ["CoffeeStyle"]
+
+
+class CoffeeStyle(Style):
+    """
+    A warm and cozy theme based off gruvbox
+    """
+
+    name = "coffee"
+
+    background_color = "#262220"
+    highlight_color = "#ddd0c0"
+
+    line_number_color = "#4e4e4e"
+    line_number_special_color = "#8f9494"
+
+    styles = {
+        Comment: "#70757A",
+        Comment.Hashbang: "#8f9f9f",
+        Comment.Preproc: "#fdd0c0",
+        Comment.PreprocFile: "#c9b98f",
+        Comment.Special: "#af5f5f",
+        Error: "#af5f5f",
+        Generic.Deleted: "#bb6868",
+        Generic.Emph: "italic",
+        Generic.Error: "#af5f5f",
+        Generic.Inserted: "#849155",
+        Generic.Output: "#ddd0c0",
+        Generic.Strong: "bold",
+        Generic.Traceback: "#af5f5f",
+        Keyword: "#919191",
+        Keyword.Constant: "#875f5f",
+        Keyword.Declaration: "#875f5f",
+        Keyword.Namespace: "#875f5f",
+        Keyword.Reserved: "#b46276",
+        Keyword.Type: "#af875f",
+        Literal: "#af875f",
+        Name: "#ddd0c0",
+        Name.Attribute: "#ddd0c0",
+        Name.Builtin: "#ddd0c0",
+        Name.Builtin.Pseudo: "#87afaf",
+        Name.Class: "#875f5f",
+        Name.Constant: "#af8787",
+        Name.Decorator: "#fdd0c0",
+        Name.Entity: "#ddd0c0",
+        Name.Exception: "#877575",
+        Name.Function: "#fdd0c0",
+        Name.Function.Magic: "#fdd0c0",
+        Name.Other: "#ddd0c0",
+        Name.Property: "#dfaf87",
+        Name.Tag: "#87afaf",
+        Name.Variable: "#ddd0c0",
+        Number: "#87afaf",
+        Operator: "#878787",
+        Operator.Word: "#878787",
+        Punctuation: "#ddd0c0",
+        String: "#c9b98f",
+        String.Affix: "#dfaf87",
+        String.Doc: "#878787",
+        String.Escape: "#af5f5f",
+        String.Interpol: "#af5f5f",
+        String.Other: "#fdd0c0",
+        String.Regex: "#af5f5f",
+        String.Symbol: "#af5f5f",
+        Token: "#ddd0c0",
+    }