refactor: replace fzf.fish modify script with Fish function wrapper

Replace Bun-based modify_ script with cleaner Fish function override that
intercepts fzf_configure_bindings at load time to disable CTRL+R binding.
Also fix Fisher update script to run_onchange for proper chezmoi behavior.

home/dot_config/fish/conf.d/00-fzf-override.fish.tmpl

@@ -0,0 +1,17 @@
+# Override fzf.fish default bindings before it loads
+# This file loads before fzf.fish (alphabetically) to prevent CTRL+R binding
+# We want Atuin to handle CTRL+R instead of fzf
+
+# Store the original fzf_configure_bindings function
+functions -c fzf_configure_bindings _fzf_configure_bindings_original 2>/dev/null
+
+# Override with our version that disables history binding
+function fzf_configure_bindings --wraps=_fzf_configure_bindings_original
+    # If called without arguments (from fzf.fish), add --history= to disable CTRL+R
+    if test (count $argv) -eq 0
+        _fzf_configure_bindings_original --history=
+    else
+        # Otherwise pass through arguments as-is
+        _fzf_configure_bindings_original $argv
+    end
+end

home/dot_config/fish/conf.d/modify_fzf.fish.tmpl

@@ -1,20 +0,0 @@
-#!/usr/bin/env bun
-
-// Modify fzf.fish to disable default CTRL+R binding (allow Atuin to handle it)
-// This is a chezmoi modify_ script that processes fzf.fish on every apply
-
-const content = await Bun.stdin.text();
-const lines = content.split('\n');
-
-// Find and comment out the standalone fzf_configure_bindings call
-const targetLineRegex = /^(\s*)fzf_configure_bindings\s*$/;
-
-const modifiedLines = lines.map(line => {
-  if (targetLineRegex.test(line) && !line.trim().startsWith('#')) {
-    const indent = line.match(/^(\s*)/)?.[1] || '';
-    return `${indent}# fzf_configure_bindings  # Disabled - configured in config.fish instead`;
-  }
-  return line;
-});
-
-console.log(modifiedLines.join('\n'));