feat(yt-dlp): add wrapper with embedding + SponsorBlock defaults

Add functions/yt-dlp.fish, shadowing yt-dlp to prepend sane defaults
(--sponsorblock-remove all, --embed-subs, --embed-metadata,
--embed-thumbnail). Each default is suppressed when the user already
passes that flag, its alias (--add-metadata), its negation
(--no-embed-thumbnail), the --opt=value form (--sponsorblock-remove=...),
or the global --no-sponsorblock kill. User args pass through last so an
explicit flag wins on precedence. Gated as a C1 opinionated alias;
falls back to bare `command yt-dlp` when disabled.

Register yt-dlp as a recommended (rec tier) dependency in the fish-deps
catalog and document the function (§5.13) and dependency in the SSOT
and index.

functions/_fish_deps_catalog.fish

@@ -16,27 +16,27 @@ function _fish_deps_catalog
     set -g _fdc_bins \
         uv cargo fish starship fzf zoxide direnv paru yay \
         wakatime tailscale \
-        eza lsd bat btop dust duf prettyping ov rg lazygit lazydocker trash kitty wezterm python3
+        eza lsd bat btop dust duf prettyping ov rg lazygit lazydocker trash kitty wezterm python3 yt-dlp
 
     set -g _fdc_tiers \
         rec rec req rec req req rec rec rec \
         int int \
-        rec rec rec rec rec rec rec rec rec rec rec rec rec rec rec
+        rec rec rec rec rec rec rec rec rec rec rec rec rec rec rec rec
 
     set -g _fdc_cargo \
         "" "" "" starship "" zoxide "" "" "" \
         "" "" \
-        eza lsd bat "" du-dust "" "" ov ripgrep "" "" trashy "" "" ""
+        eza lsd bat "" du-dust "" "" ov ripgrep "" "" trashy "" "" "" ""
 
     set -g _fdc_pm \
         uv cargo fish starship fzf zoxide direnv "" yay \
         wakatime tailscale \
-        eza lsd bat btop dust duf prettyping ov ripgrep lazygit lazydocker trash kitty wezterm python
+        eza lsd bat btop dust duf prettyping ov ripgrep lazygit lazydocker trash kitty wezterm python yt-dlp
 
     set -g _fdc_special \
         curl-uv rustup-installer git-cargo-fish curl-installer fzf-update "" "" paru-build yay-build \
         wakatime-binary "" \
-        "" "" "" "" "" "" "" "" "" "" curl-lazydocker "" "" "" ""
+        "" "" "" "" "" "" "" "" "" "" curl-lazydocker "" "" "" "" ""
 end
 
 # SYNOPSIS

functions/yt-dlp.fish

@@ -0,0 +1,61 @@
+# Copyright (C) 2026 Rootiest
+# SPDX-License-Identifier: AGPL-3.0-or-later
+
+# SYNOPSIS
+#   yt-dlp [args...] URL [URL...]
+#
+# DESCRIPTION
+#   Wraps yt-dlp, injecting sane embedding + SponsorBlock defaults
+#   (--sponsorblock-remove all, --embed-subs, --embed-metadata,
+#   --embed-thumbnail). Each default is suppressed if the user already
+#   passes that flag, its alias, or its negation (e.g. --no-embed-thumbnail
+#   drops our --embed-thumbnail). All other arguments pass through
+#   untouched. --help and friends fall through to real yt-dlp.
+#
+# ARGUMENTS
+#   args...  Arguments forwarded to yt-dlp (defaults prepended)
+#
+# EXAMPLE
+#   yt-dlp dQw4w9WgXcQ
+#   yt-dlp --no-embed-thumbnail dQw4w9WgXcQ   # drops our thumbnail default
+function yt-dlp --description 'yt-dlp with embedding + SponsorBlock defaults'
+    # Opinionated guard (C1): fall back to bare command yt-dlp when disabled.
+    if not __fish_config_op_enabled __fish_config_op_aliases
+        command yt-dlp $argv
+        return $status
+    end
+
+    set -l extra
+
+    # --embed-subs (skip if set or negated)
+    if not contains -- --embed-subs $argv
+        and not contains -- --no-embed-subs $argv
+        set -a extra --embed-subs
+    end
+
+    # --embed-thumbnail (skip if set or negated)
+    if not contains -- --embed-thumbnail $argv
+        and not contains -- --no-embed-thumbnail $argv
+        set -a extra --embed-thumbnail
+    end
+
+    # --embed-metadata (aliases: --add-metadata / --no-add-metadata)
+    if not contains -- --embed-metadata $argv
+        and not contains -- --add-metadata $argv
+        and not contains -- --no-embed-metadata $argv
+        and not contains -- --no-add-metadata $argv
+        set -a extra --embed-metadata
+    end
+
+    # --sponsorblock-remove all
+    # Skip if the user set their own remove (bare or --opt=value form), or
+    # disabled SponsorBlock entirely with --no-sponsorblock.
+    if not string match -q -- '--sponsorblock-remove' $argv
+        and not string match -q -- '--sponsorblock-remove=*' $argv
+        and not contains -- --no-sponsorblock $argv
+        set -a extra --sponsorblock-remove all
+    end
+
+    # User args last so an explicit flag wins any store_true/false precedence.
+    command yt-dlp $extra $argv
+end