fix(#795): skill_not_found and unsupported_skills_action now return non-null hints via fallback table

ROADMAP.md

@@ -7755,3 +7755,5 @@ Original filing (2026-04-18): the session emitted `SessionStart hook (completed)
 793. **`claw plugins list --bogus-flag` silent empty success + `plugins uninstall <not-found>` had `hint:null`** — dogfooded 2026-05-27 on `abfa2e4c`. Two gaps: (1) `plugins list` filter branch in `print_plugins` treated `--bogus-flag` as an id substring filter, found no matches, returned `status:"ok"` empty list — same false-positive as #792 for agents/skills. (2) `plugins uninstall no-such` propagated `plugin_not_found` error via `?` with no `\n` delimiter; `plugin_not_found` was missing from `fallback_hint_for_error_kind` table. Fix: (1) added flag-prefix guard in `print_plugins` `is_list_action` branch (detects tokens starting with `-`, returns `unknown_option` + usage hint, exits 1); (2) added `"plugin_not_found"` → `"Run 'claw plugins list' to see installed plugins."` to fallback table. Two new tests `plugins_list_flag_shaped_filter_returns_unknown_option_793`, `plugins_uninstall_not_found_has_hint_793`. 55 CLI contract tests pass. [SCOPE: claw-code] Source: Jobdori plugins lifecycle probe on `abfa2e4c`, 2026-05-27.
 
 794. **`claw plugins install /nonexistent/path` returned `error_kind:"unknown"` + `hint:null`** — dogfooded 2026-05-27 on `57a57ef7`. The error message `"plugin source '/path' was not found"` had no classifier arm, falling to `"unknown"`. Fix: added `plugin_source_not_found` classifier arm (`message.contains("plugin source") && message.contains("was not found")`); added `"plugin_source_not_found"` → `"Check that the path or URL is correct..."` to `fallback_hint_for_error_kind`. Unit test assertion added to `test_classify_error_kind`; integration test `plugins_install_not_found_path_returns_typed_kind_794` added. 56 CLI contract tests pass. [SCOPE: claw-code] Source: Jobdori plugins install probe on `57a57ef7`, 2026-05-27.
+
+795. **`claw skills install /nonexistent` returned `skill_not_found + hint:null` and `claw skills uninstall x` returned `unsupported_skills_action + hint:null`** — dogfooded 2026-05-27 on `491f179a`. Both error kinds were missing from `fallback_hint_for_error_kind` table, so even though classify returned a typed kind, the hint field was always null. Fix: added `"skill_not_found"` → hint suggesting `claw skills list` / `claw skills install`; added `"unsupported_skills_action"` → hint listing supported actions. Integration test `skills_install_not_found_and_unsupported_action_have_hints_795` covers both paths. 57 CLI contract tests pass. [SCOPE: claw-code] Source: Jobdori skills lifecycle probe on `491f179a`, 2026-05-27.

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

@@ -421,6 +421,14 @@ fn fallback_hint_for_error_kind(kind: &str) -> Option<&'static str> {
         "plugin_source_not_found" => Some(
             "Check that the path or URL is correct. Use a local directory or a valid registry id.",
         ),
+        // #795: skills install/show of a non-existing skill path or name
+        "skill_not_found" => Some(
+            "Run `claw skills list` to see available skills, or `claw skills install <path>` to install a new one.",
+        ),
+        // #795: unsupported action on skills (e.g. /skills uninstall) with no \n hint
+        "unsupported_skills_action" => Some(
+            "Supported: list, install <path>, show <name>, help. Run `claw skills help` for details.",
+        ),
         _ => None,
     }
 }

rust/crates/rusty-claude-cli/tests/output_format_contract.rs

@@ -3201,3 +3201,84 @@ fn plugins_install_not_found_path_returns_typed_kind_794() {
         .expect("plugin_source_not_found must have non-null hint (#794)");
     assert!(!h.is_empty(), "hint must be non-empty");
 }
+
+#[test]
+fn skills_install_not_found_and_unsupported_action_have_hints_795() {
+    // #795: `claw skills install /nonexistent` returned skill_not_found + hint:null, and
+    // `claw skills uninstall x` returned unsupported_skills_action + hint:null. Both error
+    // kinds were missing from fallback_hint_for_error_kind table. Fix: added both entries.
+    let root = unique_temp_dir("skills-install-795");
+    fs::create_dir_all(&root).expect("temp dir");
+    std::process::Command::new("git")
+        .args(["init", "-q"])
+        .current_dir(&root)
+        .output()
+        .ok();
+
+    // skills install with nonexistent local path
+    let out1 = run_claw(
+        &root,
+        &[
+            "--output-format",
+            "json",
+            "skills",
+            "install",
+            "/nonexistent-xyz-795",
+        ],
+        &[],
+    );
+    assert!(
+        !out1.status.success(),
+        "skills install not-found must exit non-zero (#795)"
+    );
+    let stderr1 = String::from_utf8_lossy(&out1.stderr);
+    let j1: serde_json::Value = stderr1
+        .lines()
+        .find(|l| l.trim_start().starts_with('{'))
+        .and_then(|l| serde_json::from_str(l).ok())
+        .expect("skills install not-found should emit JSON error");
+    assert_eq!(
+        j1["error_kind"], "skill_not_found",
+        "skills install not-found should be skill_not_found, got {:?}",
+        j1["error_kind"]
+    );
+    let h1 = j1["hint"]
+        .as_str()
+        .expect("skill_not_found must have non-null hint (#795)");
+    assert!(
+        h1.contains("skills list") || h1.contains("skills install"),
+        "hint should reference skills commands, got: {h1:?}"
+    );
+
+    // skills uninstall (unsupported action)
+    let out2 = run_claw(
+        &root,
+        &[
+            "--output-format",
+            "json",
+            "skills",
+            "uninstall",
+            "some-skill",
+        ],
+        &[],
+    );
+    assert!(
+        !out2.status.success(),
+        "skills uninstall must exit non-zero (#795)"
+    );
+    let stderr2 = String::from_utf8_lossy(&out2.stderr);
+    let j2: serde_json::Value = stderr2
+        .lines()
+        .find(|l| l.trim_start().starts_with('{'))
+        .and_then(|l| serde_json::from_str(l).ok())
+        .expect("skills uninstall should emit JSON error");
+    assert_eq!(
+        j2["error_kind"], "unsupported_skills_action",
+        "skills uninstall should be unsupported_skills_action, got {:?}",
+        j2["error_kind"]
+    );
+    let h2 = j2["hint"]
+        .as_str()
+        .expect("unsupported_skills_action must have non-null hint (#795)");
+    assert!(!h2.is_empty(), "hint must be non-empty");
+}