feat: add claude wrapper that auto-links AGENTS.md as CLAUDE.md

New functions/claude.fish wraps the claude CLI. Before launch it checks the
current directory and the git project root; when CLAUDE.md is absent but
AGENTS.md is present, it creates a relative symlink CLAUDE.md -> AGENTS.md so
Claude Code picks up shared agent instructions without duplicating the file.
Arguments are forwarded verbatim.

Implemented as a C1 command shadow: when __fish_config_op_aliases (or the
master __fish_config_opinionated) is disabled, the call passes through to the
bare claude binary unchanged. Link-creation notices print to stderr in green.

Documents the new shadow in docs/fish-config.md (section 5.12 AI tools, C1
component reference table, and C1 summary list) and adds a claude-cli anchor
to docs/fish-config.index.

functions/claude.fish

@@ -0,0 +1,64 @@
+# Copyright (C) 2026 Rootiest
+# SPDX-License-Identifier: AGPL-3.0-or-later
+
+# SYNOPSIS
+#   claude [ARGS...]
+#
+# DESCRIPTION
+#   Wrapper for the claude CLI that ensures CLAUDE.md exists before launch.
+#   Both the current directory and the git project root are checked. When
+#   CLAUDE.md is absent but AGENTS.md is present in a checked directory, a
+#   relative symlink CLAUDE.md -> AGENTS.md is created automatically so that
+#   Claude Code picks up shared agent instructions without duplicating the
+#   file. All arguments are forwarded verbatim to the real claude binary.
+#
+#   Opinionated component (C1): when disabled via __fish_config_op_aliases
+#   (or the __fish_config_opinionated master), the command is passed through
+#   to the real claude binary unchanged.
+#
+# ARGUMENTS
+#   ARGS  Any arguments forwarded verbatim to the underlying claude binary
+#
+# RETURNS
+#   Exit status of the underlying claude binary
+#
+# EXAMPLE
+#   claude
+#   claude --resume
+#   claude "Explain the recent changes"
+function claude --wraps=claude --description 'claude wrapper: auto-links AGENTS.md as CLAUDE.md'
+    if not __fish_config_op_enabled __fish_config_op_aliases
+        command claude $argv
+        return $status
+    end
+
+    set -l c_ok    (set_color green)
+    set -l c_reset (set_color normal)
+
+    # Build the list of directories to inspect: cwd always, git root when different.
+    set -l check_dirs (pwd)
+    set -l git_root (git rev-parse --show-toplevel 2>/dev/null)
+    if test -n "$git_root" -a "$git_root" != (pwd)
+        set check_dirs $check_dirs $git_root
+    end
+
+    # Anchor for relative display: git root when available, otherwise cwd.
+    set -l anchor $git_root
+    test -z "$anchor" && set anchor (pwd)
+
+    for dir in $check_dirs
+        if not test -e "$dir/CLAUDE.md"
+            if test -f "$dir/AGENTS.md"
+                ln -s AGENTS.md "$dir/CLAUDE.md"
+                set -l prefix ""
+                if test "$dir" != "$anchor"
+                    set prefix (string replace "$anchor/" "" "$dir")/
+                end
+                set -l msg (string join "" "→ Linked " $prefix "CLAUDE.md → " $prefix "AGENTS.md")
+                echo $c_ok$msg$c_reset >&2
+            end
+        end
+    end
+
+    command claude $argv
+end