docs: clarify that plugin functionality is bundled, not managed by fisher

Only jorgebucaran/fisher itself is in fish_plugins. The functionality
from catppuccin/fish, fzf.fish, done, autopair, and puffer-fish is
bundled directly with this config in modified form and must not be
installed or updated via fisher.

Removes sponge (not present), corrects file path mappings for bundled
components, fixes stale "Plugin sync failed" message in first_run.fish,
and expands fish-config.index with missing sections 9–11.

README.md

@@ -22,7 +22,7 @@ This config layers on top of the CachyOS base Fish configuration and adds:
 
 - **Catppuccin Mocha** theming throughout (prompt, FZF, syntax highlighting)
 - **Starship** prompt with VI key bindings
-- **Fisher** plugin management with FZF key bindings and Catppuccin syntax colors
+- **Fisher** plugin manager bootstrapped automatically; plugin functionality (FZF bindings, Catppuccin theme, done notifications, autopair, puffer-fish) bundled directly with the config
 - **Smart CLI wrappers** that prefer modern tools (`eza`, `bat`, `btop`, `dust`, `prettyping`) with graceful fallbacks
 - **Auto Python venv** activation on directory change (direnv-aware)
 - **Kitty terminal** deep integration for splits, tabs, and SSH
@@ -66,7 +66,7 @@ mv ~/.config/fish ~/.config/fish.bak
 git clone https://git.rootiest.dev/rootiest/fish-config.git ~/.config/fish
 ```
 
-Then open a new Fish shell — Fisher and all plugins will be installed automatically on first launch, and the Catppuccin Mocha theme will be applied.
+Then open a new Fish shell — Fisher will be installed automatically on first launch and the Catppuccin Mocha theme will be applied. All plugin functionality is bundled directly with this config and requires no additional installation.
 
 A [chezmoi](https://www.chezmoi.io/) dotfile manager is also configured — secrets are sourced from `~/.config/.user-dots/fish/secrets.fish` and excluded from version control.