fix(browser)!: keep malformed console argument inventories unknown (#6016)

* fix(browser)!: keep malformed console argument inventories unknown

An omitted, null, or non-array Runtime.consoleAPICalled args inventory now
reports argument_types as null, text capture as unavailable, and
console_events as invalid_protocol_value instead of a complete empty
inventory. Malformed argument elements keep their CDP position as
"unknown", so retained text values keep their original argument_index.

Call-site attribution now uses the frame at position zero: a malformed top
stack frame is no longer replaced by its caller. Console events are
excluded and request initiator locations are null, both reported as
invalid_protocol_value.

BREAKING CHANGE: console event argument_types may now be null, and
console text_capture.status may now be "unavailable", when the CDP
producer omits or malforms the argument inventory.

Fixes #5934

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

* fix(browser): report malformed WebMCP registration stacks as incomplete

topCallFrame now owns the omitted-versus-malformed decision for the whole
stack value: an omitted stack has no call site, while a non-object stack,
non-array callFrames, or a malformed top frame is malformed. WebMCP
discovery keeps the tool with a null registration_source but records
webmcp_tools invalid_protocol_value, so capture comparisons stay unknown
instead of confirming a changed source. Console and initiator stacks use
the same rule.

Refs #5934

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

---------

Co-authored-by: Claude Opus 5.5 <noreply@anthropic.com>

docs/browser-observation.md

@@ -18,7 +18,7 @@ Inspect native SAZ or HAR 1.2 offline with REA, or connect Everywhere's separate
 - `inspect_web_page` / `rea inspect-web-page` captures DOM structure, accessibility nodes, scripts, resources, safe response/DOM metadata, attach-window network and console metadata, WebSocket frame sizes, workers, quota, and optionally selected storage key names, redacted storage-content fingerprints, or script sources.
 - `analyze_web_bundle` / `rea analyze-web-bundle` parses selected script artifacts without execution and derives chunk edges, route and endpoint candidates, vendor fingerprints, static WebMCP declarations, and optionally source-map/original-source evidence.
 - `observe_web_session` / `rea observe-web-session` arms an observation window of the requested duration for an external user action and records ordered reload, SPA navigation, redirect, failure, lifecycle, and target-termination metadata.
-- `discover_webmcp_tools` / `rea discover-webmcp-tools` uses the experimental CDP WebMCP domain to return every in-scope registration and its complete observed `input_schema` declaration and canonical `input_schema_sha256` digest inline. Declarations are untrusted JSON data, including declared types, required fields, enums, examples and reference URLs. REA does not resolve schema references. These fields replace `input_schema_shape`. Registrations with the same name and URL in distinct observed frames retain separate identities. `tool_key` includes the observed frame ID; it is not a stable identity across navigation or browser sessions. Same-frame registration updates replace that owner only, and removal leaves other owners intact. Declared `readOnly`, `untrustedContent`, `consequential`, and `autosubmit` annotation hints are reported per registration: `true`/`false` are declared values, `null` means the declaration did not provide the hint in that capture, and a missing `consequential` key means the hint was not recorded, either in a historical capture or because the observed annotation was invalid. Consult discovery completeness and exclusions to distinguish these cases. Malformed annotation values retain the registration with incomplete coverage and an `invalid_protocol_value` exclusion. Other malformed protocol payloads can fail discovery explicitly. REA never exposes `WebMCP.invokeTool`.
+- `discover_webmcp_tools` / `rea discover-webmcp-tools` uses the experimental CDP WebMCP domain to return every in-scope registration and its complete observed `input_schema` declaration and canonical `input_schema_sha256` digest inline. Declarations are untrusted JSON data, including declared types, required fields, enums, examples and reference URLs. REA does not resolve schema references. These fields replace `input_schema_shape`. Registrations with the same name and URL in distinct observed frames retain separate identities. `tool_key` includes the observed frame ID; it is not a stable identity across navigation or browser sessions. Same-frame registration updates replace that owner only, and removal leaves other owners intact. Declared `readOnly`, `untrustedContent`, `consequential`, and `autosubmit` annotation hints are reported per registration: `true`/`false` are declared values, `null` means the declaration did not provide the hint in that capture, and a missing `consequential` key means the hint was not recorded, either in a historical capture or because the observed annotation was invalid. Consult discovery completeness and exclusions to distinguish these cases. Malformed annotation values or registration stacks retain the registration with incomplete coverage and an `invalid_protocol_value` exclusion. Other malformed protocol payloads can fail discovery explicitly. REA never exposes `WebMCP.invokeTool`.
 
 - `compare_web_captures` / `rea compare-web-captures` compares passive captures or exact-step-aligned browser scenarios. Scenario results commit reproducible literal normalization and expose alignment failures plus artifact-level action, screenshot, DOM, accessibility, URL, history, storage, and event differences. Missing or truncated evidence is never treated as equivalence.
 
@@ -361,7 +361,7 @@ REA retains local observation data and removes only URL userinfo credentials, ex
   WebSocket stream inventories and connection counts likewise require complete
   WebSocket coverage. Redirect resource types use only shared known metadata:
   an omitted type leaves equality unknown rather than proving a modification.
-- Console observations with a stack source retain call type, argument types, the CDP `Runtime.Timestamp` in milliseconds since Unix epoch, and source location. An absent or invalid timestamp is `null` and makes `console_events` incomplete; an observed zero remains zero. This epoch-millisecond clock is separate from the monotonic-second timestamps in `observe-web-session`. When console text capture is selected, already-delivered primitive values are retained verbatim; objects, getters, and remote properties are never expanded.
+- Console observations with a stack source retain call type, argument types, the CDP `Runtime.Timestamp` in milliseconds since Unix epoch, and source location. An absent or invalid timestamp is `null` and makes `console_events` incomplete; an observed zero remains zero. Argument types are listed by CDP argument position. An absent or non-array argument inventory is `null`, and a malformed argument keeps its position as `unknown`; either makes `console_events` incomplete, while an observed empty inventory remains `[]`. A malformed stack or top stack frame is not replaced by its caller: the console event is excluded, and a request initiator location or WebMCP `registration_source` is `null`; each is reported as `invalid_protocol_value`. This epoch-millisecond clock is separate from the monotonic-second timestamps in `observe-web-session`. When console text capture is selected, already-delivered primitive values are retained verbatim with their original `argument_index`; objects, getters, and remote properties are never expanded. Text capture is `unavailable` when the argument inventory is unknown.
 - WebSocket observations retain direction, opcode, and payload byte length. A missing or malformed CDP opcode is returned as `null`, with opcode-dependent payload byte length and shape also `null`, and marks `websocket_frames` incomplete. Missing or wrong-typed payload data is not treated as empty; its byte length is `null`, and a text payload shape is unknown. Numeric opcode `0` and an observed empty payload remain distinct from missing data. Opcode is nullable in the public inspection schema, so clients must handle unknown protocol values. When shape capture is selected, text messages are classified as text or complete value-free JSON shape; binary bytes, hashes, prefixes, and raw payloads are never retained.
 - Storage observations always redact values. Key names, IndexedDB names, and cache names require `include_storage_keys`; stable content fingerprints require the additional `include_storage_fingerprints` selection. Cookie fingerprints cover cookies applicable to the current main-frame URL, including its path, rather than every cookie path on that origin. Other storage remains scoped to the origin. Cache fingerprints hash all decoded response bytes, including bodies above 64 KiB, subject to the [64 MiB per-message CDP limit](#request-boundary). Missing or undecodable cache bodies and partial IndexedDB remote objects make fingerprint coverage incomplete, so identical observations remain `unknown`.
 - Unavailable or malformed storage inventories mark `storage_keys` unavailable, even without fingerprints. Comparisons suppress inferred key additions and removals while preserving modifications proven by complete fingerprints on both sides. Previously exported captures are not retroactively corrected; recapture them to obtain these coverage markers.