feat(config): refactor config.fish, add XDG compliance, new functions, and keybindings

Restructure and expand the Fish shell configuration for better XDG compliance,
interactive-session gating, modularity, and ergonomics.

config.fish:
- Add full XDG Base Directory variable block (XDG_CONFIG_HOME, XDG_CACHE_HOME,
  XDG_DATA_HOME, XDG_STATE_HOME) and redirect tool caches/configs accordingly
  (cargo, rustup, go, bun, npm, gnupg, wakatime, wget, nvidia, codeium, etc.)
- Add editor setup with `type -q nvim` guard and NVIM_APPNAME
- Add CDPATH block (., ~/projects, ~) with explanatory comments
- Gate all interactive-only setup (key bindings, FZF, direnv, starship, secrets,
  local overrides, CLAUDE_CODE_NO_FLICKER) behind `status is-interactive`
- Guard FZF integration source behind a file-existence check
- Move secrets.fish and local.fish sourcing into the interactive block as overrides
- Remove obsolete universal `cdp` variable and duplicate PATH/editor blocks
- Update PATH entries to use XDG-resolved $CARGO_HOME and $BUN_INSTALL

conf.d/theme.fish:
- Move FZF_DEFAULT_OPTS (Catppuccin Mocha palette) from config.fish into theme.fish
  so all theming lives in one place
- Add section header for FZF colors; condense file header comment

conf.d/abbr.fish:
- Add `/exit` abbreviation as a vim-style alias for the `exit` builtin

conf.d/key_bindings.fish:
- Bind Ctrl+Alt+= to new `qalc_eval` function (inline Qalculate! evaluation)
- Add binding in both normal and all Vi modes
- Add descriptive comment block explaining the keybinding purpose

functions/bash.fish:
- Pass `--rcfile "$XDG_CONFIG_HOME/bash/bashrc"` so bash respects XDG config location

functions/cat.fish:
- Extend cat wrapper: detect directory arguments and delegate to `ls` instead of bat
- Preserve stdin-passthrough behavior when no arguments are provided

functions/__auto_source_fallback_venv.fish (new):
- Extract auto-venv PWD watcher from config.fish into its own autoloaded function file
- Skips activation when direnv manages the directory (.envrc present or DIRENV_DIR set)
- Deactivates venv when leaving its project tree

functions/ld.fish (new):
- Wrapper for lazydocker that injects the active Docker context's DOCKER_HOST,
  enabling correct context-aware operation

functions/joplin.fish (new):
- Joplin CLI wrapper function

functions/qalc_eval.fish (new):
- Inline Qalculate! evaluator: reads the current commandline buffer, passes it to
  `qalc`, prints the result, and clears the buffer for rapid-fire math in the shell

README.md:
- Remove stale `cdp` variable example from the local.fish documentation section

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

functions/__auto_source_fallback_venv.fish

@@ -0,0 +1,27 @@
+# Copyright (C) 2026 Rootiest
+# SPDX-License-Identifier: AGPL-3.0-or-later
+
+function __auto_source_fallback_venv --on-variable PWD
+    status --is-command-substitution; and return
+    
+    # 1. Skip if direnv is already managing this directory
+    if set -q DIRENV_DIR; or test -e ".envrc"
+        return
+    end
+    
+    # 2. If we are already in a venv, check if we've left its tree
+        if set -q VIRTUAL_ENV
+                # Check if the current PWD is still within the directory that owns the venv
+                # (Assuming the venv is at the root of the project)
+                set -l venv_root (string replace -r '/.venv$' '' $VIRTUAL_ENV)
+                if not string match -q "$venv_root*" "$PWD"
+                        type -q deactivate; and deactivate
+                end
+                return
+        end
+    
+        # 3. Only source the venv if we aren't already in one
+    if test -e ".venv/bin/activate.fish"
+        source .venv/bin/activate.fish
+    end
+end

functions/bash.fish

@@ -4,6 +4,6 @@
 # bash switches to bash shell
 function bash --wraps='bash' --description 'bash switches to bash shell'
     set SHELL $(which bash) # Set shell to bash
-    command bash $argv # run bash
+    command bash --rcfile "$XDG_CONFIG_HOME/bash/bashrc" $argv # Run bash
     set SHELL $(which fish) # Reset shell
 end

functions/cat.fish

@@ -1,8 +1,18 @@
 # Copyright (C) 2026 Rootiest
 # SPDX-License-Identifier: AGPL-3.0-or-later
 
-# alias cat=bat
-function cat --wraps='bat' --description 'alias cat=bat'
+function cat --wraps='bat' --description 'Use bat for files and ls for directories'
+    # If no arguments are provided, cat usually waits for stdin. 
+    # We'll maintain that behavior by skipping the directory check if $argv is empty.
+    if set -q argv[1]
+        if test -d $argv[1]
+            # If it's a directory, run your custom ls function
+            ls $argv
+            return
+        end
+    end
+
+    # Fallback to bat or standard cat
     if type -q bat
         bat --plain --no-pager $argv
     else

functions/joplin.fish

@@ -0,0 +1,13 @@
+# Copyright (C) 2026 Rootiest
+# SPDX-License-Identifier: AGPL-3.0-or-later
+
+# Run joplin CLI without Node deprecation warnings
+function joplin --description 'Run Joplin CLI without Node deprecation warnings'
+    set -l joplin_path (command -v joplin)
+    if test -n "$joplin_path"
+        NODE_OPTIONS="--no-deprecation" $joplin_path $argv
+    else
+        echo "Error: joplin binary not found in PATH" >&2
+        return 1
+    end
+end

functions/ld.fish

@@ -0,0 +1,10 @@
+# Copyright (C) 2026 Rootiest
+# SPDX-License-Identifier: AGPL-3.0-or-later
+
+function ld --description 'Run lazydocker on the current Docker context'
+    # Fetch the host endpoint of the currently active Docker context
+    set -l current_host (docker context inspect --format '{{.Endpoints.docker.Host}}')
+
+    # Run lazydocker with the DOCKER_HOST variable set for this command only
+    env DOCKER_HOST=$current_host lazydocker
+end

functions/qalc_eval.fish

@@ -0,0 +1,19 @@
+# Copyright (C) 2026 Rootiest
+# SPDX-License-Identifier: AGPL-3.0-or-later
+
+function qalc_eval
+    # Get the current command line buffer
+    set -l cmd (commandline)
+
+    # If the buffer isn't empty, run it through qalc
+    if test -n "$cmd"
+        echo
+        # Passes the buffer to qalc
+        # -t (terse) is optional, remove it if you want the full verbose output
+        echo "$cmd" | qalc
+
+        # Clear the command line for the next task
+        commandline -r ""
+        commandline -f repaint
+    end
+end