feat(help): header-driven --help for development functions, plus the wiring guard

bd-pull, branch, check_fish_deps, claude-docs, claude-pr, fast, poke, qr
and parur take the standard call site. fish-deps instead routes -h/--help
to its existing __fish_deps_help, which previously answered only via the
unknown-subcommand path, printing "Unknown subcommand: --help" and
exiting 1.

This completes the 40 conversions and lands
test_every_user_facing_function_has_help -- acceptance criterion 6, the
check that fails when a new user-facing function ships without help. It
was developed red against the pre-conversion tree and reported exactly
the 40 names of the design's CONVERT table:

    bd-pull bkg branch check_fish_deps claude-docs claude-pr cleanup
    fast fc fish-deps fzf-update gip gip4 gip6 hist lD ld limine-edit
    lock lsr lss lstree lt ltr lx parur poke ports qr sbver screensleep
    split spwin steam-dl sudo-toggle swapstat tab tmux-clean upgrade
    wake-lock

each as "<name>: no -h/--help handling and not in $__help_exempt", with
the guard exiting 1. The count fell 40 -> 32 -> 24 -> 17 -> 10 -> 0
across the conversion commits. It is committed green so every commit on
this branch passes the suite.

$__help_exempt is the single machine-readable exemption record; a second
assertion fails if an exempt name stops being a published function, so a
rename or deletion upstream cannot silently exempt nothing.

functions/bd-pull.fish

@@ -23,6 +23,8 @@
 #   bd-pull myuser/myproject
 #   bd-pull rootiest/fish-config
 function bd-pull --description 'Pull new Gitea issues into local Beads and link them'
+    __fish_help_header (status current-function) $argv; and return 0
+
     if not set -q argv[1]; echo "Need repo owner/name"; return 1; end
     if not set -q GITEA_TOKEN; echo "\$GITEA_TOKEN not set"; return 1; end
 

functions/branch.fish

@@ -21,6 +21,8 @@
 # EXAMPLE
 #   branch feature/new-ui
 function branch --description 'Switch to or create a git branch'
+    __fish_help_header (status current-function) $argv; and return 0
+
     if not git rev-parse --is-inside-work-tree >/dev/null 2>&1
         echo "Not a git repo."
         return 1

functions/check_fish_deps.fish

@@ -14,5 +14,7 @@
 # EXAMPLE
 #   check_fish_deps
 function check_fish_deps --description 'Check all fish-related dependencies'
+    __fish_help_header (status current-function) $argv; and return 0
+
     fish-deps status
 end

functions/claude-docs.fish

@@ -15,5 +15,7 @@
 # EXAMPLE
 #   claude-docs
 function claude-docs --description 'Claude-code: Sync README with recent changes'
+    __fish_help_header (status current-function) $argv; and return 0
+
     claude "Analyze the recent changes and update the README.md to ensure all features, setup instructions, and examples are 100% accurate. Prune any obsolete information."
 end

functions/claude-pr.fish

@@ -15,5 +15,7 @@
 # EXAMPLE
 #   claude-pr
 function claude-pr --description 'Claude-code: New branch, commit, push, and PR'
+    __fish_help_header (status current-function) $argv; and return 0
+
     claude "Act as a senior engineer. Execute this sequence: 1. Create a new git branch (kebab-case). 2. Stage changes and write a Conventional Commit message. 3. Self-verify the changes by running relevant build/test commands or linting. 4. Push to remote. 5. Create a PR to 'main' including a summary of changes and a 'Manual Verification' section containing a Markdown checklist (- [ ]) of specific, bite-sized steps required to manually verify the functionality."
 end

functions/fast.fish

@@ -36,6 +36,8 @@
 # EXAMPLE
 #   fast
 function fast --description 'Placeholder for future fast utility'
+    __fish_help_header (status current-function) $argv; and return 0
+
     # ANSI Escape Codes (Standard 16-color palette)
     set -l bold "\e[1m"
     set -l italic "\e[3m"

functions/fish-deps.fish

@@ -66,6 +66,13 @@ function fish-deps --description 'Manage fish shell dependencies'
             _fish_deps_status
         case install
             _fish_deps_install $flags
+        case -h --help
+            # Reuse the existing menu rather than the header renderer: it
+            # is richer, and it is already the text the unknown-subcommand
+            # path prints. Previously --help fell into `case '*'` and
+            # exited 1 with "Unknown subcommand: --help".
+            __fish_deps_help
+            return 0
         case update
             _fish_deps_update
         case sync

functions/parur.fish

@@ -19,6 +19,8 @@
 # EXAMPLE
 #   parur
 function parur --description 'Interactively search and remove an installed package using fzf'
+    __fish_help_header (status current-function) $argv; and return 0
+
     set -l aur ""
     if type -q paru
         set aur paru

functions/poke.fish

@@ -21,6 +21,8 @@
 # EXAMPLE
 #   poke ~/projects/new/src/main.fish
 function poke --description 'touch with automatic parent directory creation'
+    __fish_help_header (status current-function) $argv; and return 0
+
     if test (count $argv) -eq 0
         echo (set_color red)"poke: no file specified"(set_color normal) >&2
         return 1

functions/qr.fish

@@ -19,6 +19,8 @@
 #   qr "https://example.com"
 #   echo "hello" | qr
 function qr --description 'Generate a QR code from text or pipe'
+    __fish_help_header (status current-function) $argv; and return 0
+
     if type -q qrencode
         if set -q argv[1]
             echo $argv | qrencode -t utf8