docs(functions): merge remaining manual-only facts into headers

Word-level diff of every manual entry against its generated counterpart
surfaced 546 tokens present in the manual and absent from the header —
losses reconcile.py missed, because it compared description length and
these headers are longer overall thanks to ARGUMENTS/RETURNS.

Merged the substantive ones (546 -> 202 residual tokens, the remainder
being synonym drift). Notable real fixes:

- git-clean: -f/--force was missing from ARGUMENTS entirely
- pkg: per-package-manager query table
- qc: cli-role rationale, role paths, --role passthrough
- config-help: site URL, xdg-open, man page path, case-insensitivity
- agents-init: idempotency, .gitignore paths, upstream pull, wrapper callers
- smart_exit: exit-builtin wiring note, $SCROLLBACK_HISTORY_DIR

The manual's claim that claude/agy pass `agents-init --agents` is stale;
both pass `--quiet` (full setup). Header wins, manual dropped.

functions/qc.fish

@@ -8,12 +8,15 @@
 #   qc [prompt...]
 #
 # DESCRIPTION
-#   Quick-chat wrapper around aichat using the "cli" role. Resolves the
-#   aichat config directory (honoring $XDG_CONFIG_HOME), creates it if
-#   missing, and installs the bundled cli-agent role as a symlink at
-#   roles/cli.md on first use. Inherits aichat's own flags and tab
-#   completions (--wraps). The function is only defined when aichat is
-#   installed.
+#   Quick-chat wrapper around the aichat LLM CLI that defaults to the "cli"
+#   role — a system prompt tuned for concise, terminal-friendly output.
+#   Resolves the aichat config directory (honoring $XDG_CONFIG_HOME), creates
+#   it if missing, and on first use installs the bundled role by symlinking
+#   scripts/cli-agent.md to $XDG_CONFIG_HOME/aichat/roles/cli.md. Inherits
+#   every aichat flag and tab completion (--wraps aichat); passing --role/-r
+#   overrides the default role, so qc forwards to aichat unchanged. The
+#   function is only defined when aichat is installed. Run `qc --help` for
+#   aichat's full flag reference with the command name rewritten to qc.
 #
 # ARGUMENTS
 #   prompt...     Prompt forwarded to aichat
@@ -24,6 +27,8 @@
 #
 # EXAMPLE
 #   qc "how do I list open ports on linux?"
+#   qc -m ollama:llama3 "explain this error"
+#   qc --role coder "refactor this function"
 if type -q aichat
     function qc --wraps aichat --description 'Quick-chat wrapper around aichat (cli role)'
         if contains -- -h $argv; or contains -- --help $argv