Rewrite file viewer with pinned gutter, syntax highlighting, and toolbar

Replace the SwiftUI-only CodeFileTextView with a UIViewRepresentable backed
by CodeFileUIView. The previous approach could not support a fixed line number
gutter while independently scrolling code content horizontally.

Changes:
- Gutter is pinned outside the horizontal scroll view and never scrolls left
- Vertical scroll is handled by a single outer UIScrollView shared by both
  the gutter and code content, keeping them in sync
- Line numbers are right-aligned in a fixed-width gutter calculated from
  the total line count
- Syntax highlighting via Splash for .swift files, with plain monospaced
  rendering as fallback for unsupported file types
- Wrap toggle persisted via AppStorage (wrapRepositoryFileLines)
- Bottom toolbar replaces the floating Share button, adding Copy All and
  Wrap toggle actions
- Copy All shows a brief checkmark confirmation that resets after 2 seconds
- Font fixed at SFMono-Regular 12pt, not scaled with Dynamic Type

Implements: https://todo.sr.ht/~ccleberg/Hutch/7

1 files changed, 1 insertions, 0 deletions

diff --git a/Hutch/App/AppStorageKeys.swift b/Hutch/App/AppStorageKeys.swift
index 708b4ce..87ec420 100644
--- a/Hutch/App/AppStorageKeys.swift
+++ b/Hutch/App/AppStorageKeys.swift
@@ -2,4 +2,5 @@
 enum AppStorageKeys {
     static let swipeActionsEnabled = "swipeActionsEnabled"
     static let activeAccountID = "activeAccountID"
+    static let wrapRepositoryFileLines = "wrapRepositoryFileLines"
 }