fix(#741): config unsupported_config_section error now populates hint field; list/show/help verbs get usage hint

ROADMAP.md

@@ -7647,3 +7647,5 @@ Original filing (2026-04-18): the session emitted `SessionStart hook (completed)
 739. **`claw skills <unknown-subcommand> --output-format json` emitted two JSON objects on stdout: first the usage envelope (`action:"help", unexpected:"X"`), then a second error abort envelope (`kind:"unknown", error:"skills command failed"`) — the `print_skills` JSON path returned `Err` on `status:"error"` responses even when the response was a normal usage-display (`action:"help"`), causing the generic error serializer to emit the second envelope** — dogfooded 2026-05-26 on `4c3cb0f3`. Fix: skip the `return Err` path when `action == "help"`; usage envelopes are informational, not fatal errors. The root prompt-dispatch gap (`claw skills bogus` → `CliAction::Prompt` → `missing_credentials` in no-creds env) is a pre-existing auth-gate-on-local-surface issue (ROADMAP #431/#449) and not addressed here. Source: Jobdori dogfood on `4c3cb0f3`, 2026-05-26.
 
 740. **Test coverage gap for ROADMAP #733: `diff_json_has_status_and_result_field_702` did not assert `changed_file_count` contract** — dogfooded 2026-05-26 on `d5f0d6ed`. The test asserts `kind`, `status`, `result`, `action`, `working_directory` but not the new `changed_file_count` field added by #733. Coverage gap: (a) no assertion that the field exists, (b) no assertion of numeric type in git repos, (c) no regression guard for dedupe behavior (staged+unstaged to the same file = 1 changed file). Fix: extend the test to assert `changed_file_count: null` in non-git repos and `changed_file_count: u64` in git repos. Source: gaebal-gajae dogfood on `d5f0d6ed`, 2026-05-26.
+
+741. **`claw config list`, `claw config show`, `claw config bogus` --output-format json returned `hint: null` — the unsupported_config_section error envelope had no `hint` field populated, so callers reading `.hint` get null with no actionable guidance** — dogfooded 2026-05-26 on `5d072d21`. The `render_config_json` unsupported-section branch returned a JSON object with `error` (contains the section list) but no `hint` field. Notably `config list` and `config show` are natural verb patterns that users type expecting a list/show subcommand, but claw config uses `claw config` (no args) for list and `claw config <section>` for show — the error gave no indication of this. Fix: add `hint` field to unsupported_config_section error; verbs (`list`, `show`, `help`, `info`) get a hint explaining the correct idiom (`claw config` / `claw config <section>`); other unknown sections get a "not a config section" hint listing valid values. Source: Jobdori dogfood on `5d072d21`, 2026-05-26.

rust/crates/rusty-claude-cli/src/main.rs

@@ -7791,6 +7791,17 @@ fn render_config_json(
             "skills" => runtime_config.get("skills").map(|v| v.render()),
             "agents" => runtime_config.get("agents").map(|v| v.render()),
             other => {
+                // #741: populate hint field for unsupported section errors so callers reading
+                // .hint get actionable guidance instead of null
+                let hint = if matches!(other, "list" | "show" | "help" | "info") {
+                    format!(
+                        "'claw config {other}' is not a subcommand. To list all config: `claw config`. To inspect a section: `claw config <section>` where section is one of: env, hooks, model, plugins, mcp, sandbox, permissions, skills, agents."
+                    )
+                } else {
+                    format!(
+                        "'{other}' is not a config section. Supported: env, hooks, model, plugins, mcp, sandbox, permissions, skills, agents."
+                    )
+                };
                 return Ok(serde_json::json!({
                     "kind": "config",
                     "action": "show",
@@ -7799,6 +7810,7 @@ fn render_config_json(
                     "section": other,
                     "ok": false,
                     "error": format!("Unsupported config section '{other}'. Use: env, hooks, model, plugins, mcp, sandbox, permissions, skills, or agents."),
+                    "hint": hint,
                     "supported_sections": ["env", "hooks", "model", "plugins", "mcp", "sandbox", "permissions", "skills", "agents"],
                     "cwd": cwd.display().to_string(),
                     "loaded_files": loaded_paths.len(),