feat(buzz-cli): render an agent-friendly command tree in --help (#7584)

## Summary

`crates/buzz-acp/src/base_prompt.md` carries a hand-maintained `Group |
Key commands` table of the `buzz` CLI. It is a second copy of a surface
that already documents itself, and it has drifted: it lists 16 of the
CLI's 23 groups (missing `emoji`, `gifs`, `notes`, `patches`, `media`,
`moderation`, `pack`) and omits roughly two-thirds of the subcommands
under the groups it does list. its hard to keep it in sync.

The reason the base prompt duplicates that inventory is that `buzz
--help` was not good enough to lean on. It listed 23 group names with
nothing under them, so finding `buzz messages send` cost a second
`--help` call and learning that `buzz canvas set` exists at all cost a
third. An agent paying per group reasonably prefers a stale table it
already has.

This PR fixes the help output so the prompt can point at it instead.
`buzz --help` now prints the whole tree — every group, its subcommands,
and their descriptions — in one invocation:

**Before**

```
Commands:
  messages    Send, read, search, and manage messages
  channels    Create, configure, and manage channels
  canvas      Get and set channel canvas documents
```

**After**

```
Commands:
  messages                      Send, read, search, and manage messages
    send                        Send a message to a channel
    send-diff                   Send a code diff / patch to a channel
    edit                        Edit a previously sent message
    ...
  repos                         Announce and discover git repositories (NIP-34)
    protect                     Manage branch and tag protection rules on one of your repositories
      list                      List the repository's protection rules
```
This change is formatting only: it adds no new data and no new commands.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Signed-off-by: Salman Mohammed <smohammed@squareup.com>

crates/buzz-cli/README.md

@@ -112,6 +112,12 @@ stored rules in `validation_error` so an owner can remove and repair them.
 
 ## Commands
 
+`buzz --help` prints this whole surface as an indented tree — every group with
+its subcommands and their descriptions — so there is no need to run `--help`
+once per group to find a command. `buzz -h` keeps the short group-level
+summary, and `buzz <group> <subcommand> --help` has the flags and examples.
+The table below mirrors that tree for readers who are not at a terminal.
+
 | Group | Subcommand | Description |
 |-------|-----------|-------------|
 | `messages` | `send` | Send a message to a channel |

crates/buzz-cli/src/help_tree.rs

@@ -0,0 +1,214 @@
+//! Agent-friendly rendering of the `buzz` command tree.
+//!
+//! `buzz --help` lists every group *and* the subcommands under it, so a caller
+//! learns the whole surface in one invocation instead of one `--help` call per
+//! group. The tree is walked from clap's own command definition, so it cannot
+//! drift from the commands that actually exist.
+
+use clap::Command;
+
+/// Column (0-indexed, in characters) where descriptions begin.
+const DESC_COL: usize = 32;
+
+/// Total line width. This matches clap's own default when its `wrap_help`
+/// feature is off, which is how this crate builds clap.
+const LINE_WIDTH: usize = 100;
+
+/// Render the subcommand tree under `cmd`, descending at most `max_depth`
+/// levels. `max_depth == 1` lists only the top-level groups.
+///
+/// The returned string has one entry per line and no trailing newline.
+pub(crate) fn render(cmd: &Command, max_depth: usize) -> String {
+    let mut out = String::new();
+    write_level(&mut out, cmd, 1, max_depth);
+    out.truncate(out.trim_end().len());
+    out
+}
+
+fn write_level(out: &mut String, parent: &Command, depth: usize, max_depth: usize) {
+    if depth > max_depth {
+        return;
+    }
+    let mut children: Vec<&Command> = parent
+        .get_subcommands()
+        // clap's auto-generated `help` subcommand tells a reader nothing about
+        // what the CLI can do, and it repeats at every level of the tree.
+        .filter(|child| !child.is_hide_set() && child.get_name() != "help")
+        .collect();
+    // Match clap's own ordering: the derive assigns a display order per
+    // variant, so this preserves declaration order, with the name as tiebreak.
+    children.sort_by_key(|child| (child.get_display_order(), child.get_name()));
+
+    for child in children {
+        write_entry(out, child, depth);
+        write_level(out, child, depth + 1, max_depth);
+    }
+}
+
+fn write_entry(out: &mut String, cmd: &Command, depth: usize) {
+    let left = format!("{}{}", "  ".repeat(depth), cmd.get_name());
+    let description = description_of(cmd);
+
+    if description.is_empty() {
+        out.push_str(&left);
+        out.push('\n');
+        return;
+    }
+
+    let pad = DESC_COL.saturating_sub(left.chars().count()).max(1);
+    let mut lines = wrap(&description, LINE_WIDTH.saturating_sub(DESC_COL)).into_iter();
+
+    // `wrap` returns at least one line for non-empty input, but fall back to
+    // the bare name rather than dropping the entry if that ever changes.
+    let Some(first) = lines.next() else {
+        out.push_str(&left);
+        out.push('\n');
+        return;
+    };
+    out.push_str(&left);
+    out.push_str(&" ".repeat(pad));
+    out.push_str(&first);
+    out.push('\n');
+
+    for line in lines {
+        out.push_str(&" ".repeat(DESC_COL));
+        out.push_str(&line);
+        out.push('\n');
+    }
+}
+
+/// A command's one-line description, prefixed with its visible aliases.
+fn description_of(cmd: &Command) -> String {
+    let mut description = String::new();
+    let aliases: Vec<&str> = cmd.get_visible_aliases().collect();
+    if !aliases.is_empty() {
+        description.push_str(&format!("[alias: {}] ", aliases.join(", ")));
+    }
+    if let Some(about) = cmd.get_about() {
+        description.push_str(&about.to_string());
+    }
+    description.trim_end().to_string()
+}
+
+/// Greedy word wrap. Words longer than `width` overflow rather than break.
+fn wrap(text: &str, width: usize) -> Vec<String> {
+    let mut lines = Vec::new();
+    let mut current = String::new();
+    for word in text.split_whitespace() {
+        if current.is_empty() {
+            current.push_str(word);
+        } else if current.chars().count() + 1 + word.chars().count() <= width {
+            current.push(' ');
+            current.push_str(word);
+        } else {
+            lines.push(std::mem::take(&mut current));
+            current.push_str(word);
+        }
+    }
+    if !current.is_empty() {
+        lines.push(current);
+    }
+    lines
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use crate::build_command;
+
+    // These assertions are deliberately column-exact. clap runs
+    // `StyledStr::wrap` over `after_help`, which is a no-op only because this
+    // crate builds clap without the `wrap_help` feature; if workspace feature
+    // unification ever turns that on, clap reflows the tree and destroys the
+    // alignment. A looser `contains("send")` assertion would not notice.
+    #[test]
+    fn long_help_lists_each_group_with_its_subcommands() {
+        let help = build_command().render_long_help().to_string();
+
+        assert!(
+            help.contains(
+                "\n  messages                      Send, read, search, and manage messages\n"
+            ),
+            "group line missing or misaligned:\n{help}"
+        );
+        assert!(
+            help.contains("\n    send                        Send a message to a channel\n"),
+            "subcommand line missing or misaligned:\n{help}"
+        );
+        assert!(
+            help.contains("\n    draft-create                Open a prefilled create-agent form in the owner's Buzz Desktop\n"),
+            "subcommand line missing or misaligned:\n{help}"
+        );
+    }
+
+    #[test]
+    fn long_help_descends_past_the_second_level() {
+        let help = build_command().render_long_help().to_string();
+
+        assert!(
+            help.contains("\n    protect                     Manage branch and tag protection rules on one of your repositories\n"),
+            "nested group line missing or misaligned:\n{help}"
+        );
+        assert!(
+            help.contains(
+                "\n      list                      List the repository's protection rules\n"
+            ),
+            "third-level line missing or misaligned:\n{help}"
+        );
+    }
+
+    #[test]
+    fn long_help_wraps_long_descriptions_into_the_description_column() {
+        let help = build_command().render_long_help().to_string();
+
+        assert!(
+            help.contains(
+                "\n  emoji                         Manage your custom emoji set (workspace palette is the union of all\n                                members' sets)\n"
+            ),
+            "wrapped description missing or misaligned:\n{help}"
+        );
+    }
+
+    #[test]
+    fn short_help_stays_at_the_group_level() {
+        let help = build_command().render_help().to_string();
+
+        assert!(
+            help.contains(
+                "\n  messages                      Send, read, search, and manage messages\n"
+            ),
+            "group line missing from short help:\n{help}"
+        );
+        assert!(
+            !help.contains("\n    send "),
+            "short help should not descend into subcommands:\n{help}"
+        );
+    }
+
+    #[test]
+    fn tree_omits_claps_generated_help_subcommand() {
+        let tree = render(&build_command(), usize::MAX);
+
+        assert!(!tree.lines().any(|line| line.trim() == "help"));
+        assert!(!tree.contains("Print this message or the help of the given subcommand"));
+    }
+
+    #[test]
+    fn depth_one_lists_groups_only() {
+        let cmd = build_command();
+        let groups = render(&cmd, 1);
+
+        assert!(groups.contains("\n  messages "));
+        assert!(!groups.contains("\n    send "));
+    }
+
+    #[test]
+    fn wrap_keeps_words_intact_and_respects_width() {
+        assert_eq!(wrap("", 10), Vec::<String>::new());
+        assert_eq!(wrap("one two three", 7), vec!["one two", "three"]);
+        assert_eq!(
+            wrap("supercalifragilistic x", 5),
+            vec!["supercalifragilistic", "x"]
+        );
+    }
+}

crates/buzz-cli/src/lib.rs

@@ -2,10 +2,11 @@ pub mod agent_management;
 mod client;
 mod commands;
 mod error;
+mod help_tree;
 mod links;
 mod validate;
 
-use clap::{Parser, Subcommand};
+use clap::{CommandFactory, FromArgMatches, Parser, Subcommand};
 use client::BuzzClient;
 use error::CliError;
 use nostr::Keys;
@@ -38,7 +39,7 @@ where
     // double-install returns Err and is harmless.
     let _ = rustls::crypto::ring::default_provider().install_default();
 
-    let cli = match Cli::try_parse_from(args) {
+    let cli = match parse_args(args) {
         Ok(cli) => cli,
         Err(e) => {
             if e.use_stderr() {
@@ -60,6 +61,41 @@ where
     }
 }
 
+/// Root help layout. Identical to clap's default except that `{subcommands}`
+/// is dropped and the command tree arrives through `{after-help}` instead, so
+/// the group list is not printed twice. `{options}` and `{subcommands}` emit no
+/// heading of their own — clap writes those from `write_all_args`, which this
+/// template bypasses — so the headings are spelled out here.
+const ROOT_HELP_TEMPLATE: &str = "\
+{before-help}{about-with-newline}
+{usage-heading} {usage}{after-help}
+
+Options:
+{options}";
+
+/// The root command with the agent-friendly command tree installed.
+///
+/// clap picks `after_long_help` for `--help` and falls back to `after_help`
+/// for `-h`, which is what gives the two depths: `-h` keeps the group-level
+/// summary, `--help` shows every subcommand under every group.
+fn build_command() -> clap::Command {
+    let cmd = Cli::command();
+    let groups = help_tree::render(&cmd, 1);
+    let full = help_tree::render(&cmd, usize::MAX);
+    cmd.help_template(ROOT_HELP_TEMPLATE)
+        .after_help(format!("Commands:\n{groups}"))
+        .after_long_help(format!("Commands:\n{full}"))
+}
+
+fn parse_args<I, S>(args: I) -> Result<Cli, clap::Error>
+where
+    I: IntoIterator<Item = S>,
+    S: Into<std::ffi::OsString> + Clone,
+{
+    let matches = build_command().try_get_matches_from(args)?;
+    Cli::from_arg_matches(&matches)
+}
+
 #[derive(Parser)]
 #[command(
     name = "buzz",