fix(#20): heid-bug-hunt fixups — CLI open-world container-type hardening (slice-5)

Panel (Gróa + Hulda + Regin, source-verified by Heid): adapter/route-map/
ConnectFailed-at-call-sites sound against the declared invariants; 4 real
robustness findings, all in the CLI open-world presenter/probe paths — the
container-type layer BELOW the null/element holes the code-review already fixed.

Fixed (findings 1-3):
- `_format_whoami` (`cli.py`): a non-iterable `scopes`/`allowed_roles` scalar
  (`{"scopes": 123}`) made `x or []` yield `123` → `for s in 123` TypeError. New
  `_display_seq` helper degrades any non-list (scalar / bare string / null / absent)
  to empty; applied to both `scopes` and `allowed_roles`.
- `_characters_probe` (`cli.py`): same class on the model catalog `items` (`{"items":
  123}`) — now guards `models` is a Mapping and `items` is a list before iterating.
- `_characters_probe`: the top-level open-world reads `created` / `state` are now
  `isinstance(_, Mapping)`-guarded before any `.get` — a non-mapping SDK passthrough
  (`created=[...]`) aborts cleanly (exit 20) / renders `pad=None` instead of an
  AttributeError.

Accepted (finding 4, documented in contract § slice-5 notes): the `--characters`
probe leaks its transient character on a mid-lifecycle failure. PRE-EXISTING (the
retired probe had the identical linear no-`finally` structure — cutover did not
worsen it), TTL-bounded, one-shot diagnostic; a `try/finally` would swallow a
happy-path delete-failure (delete is both teardown and a tested step). Gróa + Heid
concur accept is defensible.

Dismissed (finding 5): Hulda flagged `sessions.py` dropping `get_me`/etc. as a
caller-contract break — it is the intended DEC-3 no-backwards-compat migration (all
in-repo callers rewired same-diff); Heid labels it intended-surface-change.

Added CLI tests for the three hardened paths (scalar scopes/roles; scalar items +
non-mapping state; non-mapping create abort). Suite 488 green; ruff clean; live
smoke re-run clean (identical happy-path output). Patch bump 0.21.17 → 0.21.18.

docs/contracts/worldtree_sdk_cutover.contract.md

@@ -274,6 +274,23 @@ re-anchor its coverage-map rows.
   is already hardened (slice-4 heid bug-hunt). The rewired `_characters_probe` extracts
   the created id defensively (`created.get("character_id")` + type-guard → clean abort,
   never a hard-index KeyError) since the create ACK is now an open-world SDK read.
+- **Container-type hardening (heid code-review + bug-hunt slice-5).** The degrade-not-
+  crash floor is guarded at THREE levels for the CLI presenters, not just one: (a) the
+  list-typed fields `scopes` / `allowed_roles` / model `items` degrade a non-list scalar
+  (`123`) or a bare string to empty via `_display_seq` / an `isinstance(_, list)` guard —
+  the older `or []` idiom only caught null/absent and would `for x in 123` `TypeError`;
+  (b) each element is type-guarded (`isinstance(m, dict)`); (c) the top-level open-world
+  reads `created` / `models` / `state` are `isinstance(_, Mapping)`-guarded before any
+  `.get` (a non-mapping passthrough would otherwise `AttributeError`). All three feed
+  `--whoami` / `--characters` only.
+- **Accepted (not fixed): the `--characters` probe leaks its transient character on a
+  mid-lifecycle failure.** create → get-state → delete runs linearly with no `finally`,
+  so a state/delete failure after a successful create orphans the probe character until
+  its TTL. This is PRE-EXISTING (the retired hand-rolled probe had the identical
+  structure — the cutover did not worsen it), TTL-bounded, and `--characters` is a
+  one-shot diagnostic smoke; a `try/finally` cleanup would also swallow a happy-path
+  delete-failure (delete is both the teardown AND a tested lifecycle step). Accepted as
+  known-risk per the heid bug-hunt (Gróa + Heid concur accept is defensible).
 - **CLI-only rewire.** `me` / `capabilities` / `characters` / `models` have NO
   web-server caller — only the `--whoami` and `--characters` CLI one-shot probes. The
   web surface is untouched this slice.

pyproject.toml

@@ -4,7 +4,7 @@ build-backend = "hatchling.build"
 
 [project]
 name = "ratatoskr"
-version = "0.21.16"
+version = "0.21.18"
 description = "Worldtree Conversation API debug console (web + headless CLI) — multi-pane observability"
 readme = "README.md"
 requires-python = ">=3.12"

src/ratatoskr/cli.py

@@ -745,12 +745,29 @@ async def _amain(args: ParsedArgs) -> int:
             loop.remove_signal_handler(signal.SIGINT)
 
 
+def _display_seq(value: Any) -> list[str]:
+    """Coerce an open-world wire value to a list of display strings — the degrade-not-
+    crash floor for a list-typed field (`scopes`, `allowed_roles`, model `items`, ...).
+
+    A non-list scalar (absent, null, `123`, or a bare string) → empty rather than a
+    crash: the older `or []` idiom handles absent/null but NOT a truthy non-iterable
+    (`123 or [] == 123` → `for x in 123` `TypeError`) and would char-iterate a bare
+    string. Only a genuine list/tuple is str-mapped (heid bug-hunt slice-5, findings 1-2).
+    """
+    if not isinstance(value, (list, tuple)):
+        return []
+    return [str(x) for x in value]
+
+
 def _format_whoami(me: Mapping[str, Any], caps: Mapping[str, Any]) -> str:
     """Render the --whoami report: identity (GET /me) + server capabilities."""
     lines = ["identity:"]
     lines.append(f"  user_id: {me.get('user_id', '?')}")
     lines.append(f"  tier: {me.get('tier', '?')}")
-    lines.append(f"  scopes: {', '.join(me.get('scopes', [])) or '(none)'}")
+    # Open-world read: `scopes` may be absent, null, a scalar, or carry non-strings —
+    # `_display_seq` degrades every non-list to empty (the contract names this function
+    # the degrade-not-crash exemplar; heid code-review + bug-hunt slice-5).
+    lines.append(f"  scopes: {', '.join(_display_seq(me.get('scopes'))) or '(none)'}")
     for k in ("display_name", "key_id", "key_label"):
         if k in me:
             lines.append(f"  {k}: {me[k]}")
@@ -759,16 +776,17 @@ def _format_whoami(me: Mapping[str, Any], caps: Mapping[str, Any]) -> str:
     if isinstance(templates, dict) and templates:
         for name, spec in templates.items():
             # A diagnostic renderer must tolerate a malformed / partially-cutover
-            # server (heid bug-hunt Gróa#1/#2): a non-mapping template value, or an
+            # server: a non-mapping template value, or an `allowed_roles` that is null
-            # explicit-null `allowed_roles` (`.get(k, [])` returns None on null, not
+            # / a scalar / carries non-strings, must degrade — not abort the whole
-            # the default), must degrade — not abort the whole --whoami report.
+            # --whoami report (heid bug-hunt slice-5: `_display_seq` guards the
+            # container type, not just null/element as the prior `or []` did).
             if not isinstance(spec, dict):
                 lines.append(f"  ephemeral_template {name}: (malformed)")
                 continue
             # Canonical post-cutover shape (worldtree-dev althing 2026-07-18,
             # ADR-0012): roles, not models. `config.role` selects; `config.model`
             # is now rejected server-side.
-            roles = ", ".join(str(r) for r in (spec.get("allowed_roles") or []))
+            roles = ", ".join(_display_seq(spec.get("allowed_roles")))
             lines.append(
                 f"  ephemeral_template {name}: default={spec.get('default_role', '?')} "
                 f"max_bytes={spec.get('system_prompt_max_bytes', '?')} roles=[{roles}]"
@@ -828,10 +846,15 @@ async def _characters_probe(args: ParsedArgs) -> int:
         client = wt.build_client(args.server_url, api_key=args.api_key, transport=transport)
         try:
             models = await wt.list_character_models(client)
-            # Open-world read: `items` may be absent OR explicit-null — `or []` degrades
+            # Open-world reads degrade, never crash (heid code-review + bug-hunt slice-5):
-            # both to empty (mirrors the slice-4 `_format_whoami` hardening), never a
+            # guard the top-level `models` is a mapping AND `items` is a list before
-            # `join(None)` crash.
+            # iterating (a scalar `items: 123` makes `... or []` yield `123` → `for m in
-            names = ", ".join(m.get("name", "?") for m in (models.get("items") or []))
+            # 123` TypeError), then guard each entry is a dict with a str-coerced `name`.
+            raw_items = models.get("items") if isinstance(models, Mapping) else None
+            items = raw_items if isinstance(raw_items, (list, tuple)) else []
+            names = ", ".join(
+                str(m.get("name", "?")) for m in items if isinstance(m, dict)
+            )
             sys.stdout.write(f"character models: {names or '(none)'}\n")
             created = await wt.create_character(
                 client,
@@ -848,9 +871,11 @@ async def _characters_probe(args: ParsedArgs) -> int:
                 },
             )
             # Open-world create ACK: degrade, don't hard-index (cumulative cutover
-            # foot-gun). A malformed/absent character_id aborts the probe cleanly rather
+            # foot-gun). A non-mapping ACK or an absent/blank character_id aborts the
-            # than raising a KeyError — the lifecycle needs the id for state + delete.
+            # probe cleanly (exit 20) rather than raising AttributeError/KeyError — the
-            cid = created.get("character_id")
+            # lifecycle needs the id for state + delete (heid bug-hunt slice-5). Past the
+            # guard, `created`/`state` are known mappings.
+            cid = created.get("character_id") if isinstance(created, Mapping) else None
             if not (isinstance(cid, str) and cid):
                 sys.stderr.write(
                     f"[session_api_failed] create returned no character_id: {created!r}\n"
@@ -858,7 +883,8 @@ async def _characters_probe(args: ParsedArgs) -> int:
                 return 20
             sys.stdout.write(f"created: {cid} (ttl {created.get('ttl_expires_at')})\n")
             state = await wt.get_character_state(client, cid)
-            sys.stdout.write(f"state: pad={state.get('pad')}\n")
+            pad = state.get("pad") if isinstance(state, Mapping) else None
+            sys.stdout.write(f"state: pad={pad}\n")
             await wt.delete_character(client, cid)
             sys.stdout.write(f"deleted: {cid}\n")
         except wt.SessionApiFailed as exc:

tests/test_cli.py

@@ -1879,6 +1879,49 @@ class TestWhoami:
         assert rc == 20
         assert "[session_api_failed]" in capsys.readouterr().err
 
+    @respx.mock
+    def test_whoami_tolerates_null_and_nonstring_scopes(
+        self, capsys: pytest.CaptureFixture[str]
+    ) -> None:
+        """scopes present-null / non-string → renders '(none)' or str-coerced, never a
+        `join(None)` TypeError (heid-code-review slice-5: `_format_whoami` is the
+        contract's degrade-not-crash exemplar; `allowed_roles` was hardened, `scopes`
+        was not)."""
+        # scopes: null (present, not absent) → `.get('scopes', [])` would return None.
+        respx.get("https://w.example/me").mock(
+            return_value=httpx.Response(200, json={"user_id": "u", "scopes": None, "tier": "user"})
+        )
+        respx.get("https://w.example/capabilities").mock(
+            return_value=httpx.Response(200, json={"ephemeral_templates": {}})
+        )
+        rc = main(["--whoami", "--api-key", "k", "--server", "https://w.example"])
+        assert rc == 0
+        assert "scopes: (none)" in capsys.readouterr().out
+
+    @respx.mock
+    def test_whoami_tolerates_scalar_scopes_and_roles(
+        self, capsys: pytest.CaptureFixture[str]
+    ) -> None:
+        """Non-iterable (scalar) `scopes` / `allowed_roles` → degrade to empty, never a
+        `for x in 123` TypeError (heid bug-hunt slice-5: `_display_seq` guards the
+        container TYPE, the next layer past the code-review null/element fix)."""
+        respx.get("https://w.example/me").mock(
+            return_value=httpx.Response(200, json={"user_id": "u", "scopes": 123, "tier": "user"})
+        )
+        respx.get("https://w.example/capabilities").mock(
+            return_value=httpx.Response(
+                200,
+                json={
+                    "ephemeral_templates": {"echo": {"allowed_roles": 7, "default_role": "echo"}}
+                },
+            )
+        )
+        rc = main(["--whoami", "--api-key", "k", "--server", "https://w.example"])
+        assert rc == 0
+        out = capsys.readouterr().out
+        assert "scopes: (none)" in out
+        assert "roles=[]" in out
+
 
 class TestTier2Probes:
     """--characters + --set-persona-pad one-shot probes (Tier-2: #161 + persona_state-write)."""
@@ -1923,6 +1966,60 @@ class TestTier2Probes:
         assert "deleted: char_z" in out
         assert del_route.call_count == 1  # lifecycle cleaned up
 
+    @respx.mock
+    def test_characters_probe_tolerates_malformed_models(
+        self, capsys: pytest.CaptureFixture[str]
+    ) -> None:
+        """models catalog with non-mapping / non-string-name items → degrades (no
+        AttributeError/TypeError), lifecycle still proceeds (heid-code-review slice-5:
+        element-level completion of the list-level `or []` guard)."""
+        respx.get("https://w.example/models/available-for-characters").mock(
+            return_value=httpx.Response(
+                200, json={"items": [None, "x", {"name": 123}, {"name": "ok"}]}
+            )
+        )
+        respx.post("https://w.example/characters").mock(
+            return_value=httpx.Response(201, json={"character_id": "c1", "ttl_expires_at": "t"})
+        )
+        respx.get("https://w.example/characters/c1/state").mock(
+            return_value=httpx.Response(200, json={"pad": [0.0, 0.0, 0.0]})
+        )
+        respx.delete("https://w.example/characters/c1").mock(return_value=httpx.Response(204))
+        rc = main(["--characters", "--api-key", "k", "--server", "https://w.example"])
+        assert rc == 0
+        out = capsys.readouterr().out
+        # non-mappings dropped; {"name":123}→"123", {"name":"ok"}→"ok" — no crash.
+        assert "character models: 123, ok" in out
+        assert "created: c1" in out
+
+    @respx.mock
+    def test_characters_probe_tolerates_scalar_items_and_nonmapping_state(
+        self, capsys: pytest.CaptureFixture[str]
+    ) -> None:
+        """Scalar `items` (`123`) → '(none)' not a `for m in 123` TypeError; a non-mapping
+        `state` → 'pad=None' not an AttributeError. Lifecycle still completes (heid
+        bug-hunt slice-5: container-type + top-level-mapping guards)."""
+        respx.get("https://w.example/models/available-for-characters").mock(
+            return_value=httpx.Response(200, json={"items": 123})
+        )
+        respx.post("https://w.example/characters").mock(
+            return_value=httpx.Response(201, json={"character_id": "c1", "ttl_expires_at": "t"})
+        )
+        # non-mapping state body (open-world passthrough of a JSON array).
+        respx.get("https://w.example/characters/c1/state").mock(
+            return_value=httpx.Response(200, json=["not", "a", "mapping"])
+        )
+        del_route = respx.delete("https://w.example/characters/c1").mock(
+            return_value=httpx.Response(204)
+        )
+        rc = main(["--characters", "--api-key", "k", "--server", "https://w.example"])
+        assert rc == 0
+        out = capsys.readouterr().out
+        assert "character models: (none)" in out
+        assert "state: pad=None" in out
+        assert "deleted: c1" in out
+        assert del_route.call_count == 1
+
     @respx.mock
     def test_characters_probe_create_missing_id_aborts(
         self, capsys: pytest.CaptureFixture[str]
@@ -1944,6 +2041,27 @@ class TestTier2Probes:
         assert "no character_id" in capsys.readouterr().err
         assert del_route.call_count == 0  # aborted before state/delete — nothing to clean
 
+    @respx.mock
+    def test_characters_probe_non_mapping_create_aborts(
+        self, capsys: pytest.CaptureFixture[str]
+    ) -> None:
+        """A non-mapping create ACK (open-world passthrough of a JSON array/scalar) →
+        clean exit-20 abort, never an AttributeError on `created.get(...)` (heid
+        bug-hunt slice-5, finding #3)."""
+        respx.get("https://w.example/models/available-for-characters").mock(
+            return_value=httpx.Response(200, json={"items": []})
+        )
+        respx.post("https://w.example/characters").mock(
+            return_value=httpx.Response(201, json=["not", "a", "mapping"])
+        )
+        del_route = respx.delete(url__regex=r"https://w\.example/characters/.+").mock(
+            return_value=httpx.Response(204)
+        )
+        rc = main(["--characters", "--api-key", "k", "--server", "https://w.example"])
+        assert rc == 20
+        assert "no character_id" in capsys.readouterr().err
+        assert del_route.call_count == 0
+
     @respx.mock
     def test_set_persona_probe(self, capsys: pytest.CaptureFixture[str]) -> None:
         """set_persona_probe [happy,tracer]: POST pad to /sessions/{id}/persona_state; 204."""

uv.lock

@@ -472,7 +472,7 @@ wheels = [
 
 [[package]]
 name = "ratatoskr"
-version = "0.21.16"
+version = "0.21.18"
 source = { editable = "." }
 dependencies = [
     { name = "httpx" },