Update client layout instrumentation

[shawj0]

Summary

• Add lightweight signal capture for a small set of exact client-control indicators.
• Reuse the existing layout discovery and mutation traversal.
• Emit newly observed values through typed client Dimension 39.
• Publish the package as 0.8.70-beta for a beta rollout.

Why

Downstream processing needs a compact page-level indication when these controls are present. Capturing the values during the traversal that already processes layout changes avoids a second DOM scan.

The typed Dimension path provides a compact numeric wire contract and owns per-page deduplication. It avoids using customer events, click telemetry, or the generic system-variable namespace.

Behavior

Scenario	Result
Indicator exists during initial discovery	Dimension value emitted once
Indicator is added or updated later	New Dimension value emitted
Short-lived indicator is removed before upload	Value retained
Indicator appears in an open shadow root or same-origin iframe	Value emitted
Same indicator is encountered again	No duplicate value
Similar or unrelated IDs	No value emitted
No indicators present	Existing behavior unchanged

Not changed

• No additional observer, polling loop, or selector scan.
• No click, custom-event, or customer-variable changes.
• No backend processing or routing changes in this repository.
• Existing privacy, consent, and startup checks remain unchanged.

Validation

• 8 focused marker scenarios passed.
• Sparse-payload smoke passed: initial discovery emitted one value, quiet payloads emitted none, and a later mutation emitted only its new value.
• Live-page local-bundle smoke passed on Microsoft, MSN, and Bing with Dimension 39 present once and no legacy ABS variable.
• 28 clarity-js package tests passed when excluding the existing consent-cookie timing flake.
• The unrelated masking input timing failures reproduced identically on untouched 0.8.69.
• 208 paired performance measurements found no repeatable INP, PLT, long-task, discovery, or mutation-cost regression.
• Bundle delta: +303 raw bytes and +112 gzip bytes.

Backend contract

Decode should add matching ClientDimension.AgenticBrowserSignal = 39 and route values 1-5 to the session classifier. Unknown Dimension 39 is safely ignored by older Decode builds during rolling deployment.

Risk and rollout

Risk is limited by exact matching, typed values, Dimension-level deduplication, and reuse of the current traversal. Publish 0.8.70-beta through the normal beta flight, monitor value distribution and client performance, and roll back by disabling the flight if needed.

[Copilot]

Pull request overview

This PR adds lightweight detection of a small set of exact “agentic browser” DOM markers during existing layout discovery/mutation processing, emitting a page-level variable signal (<!>ABS) once per detected marker. It also bumps the monorepo/package versions to 0.8.70 for beta rollout.

Changes:

• Add layout/agent marker detection and wire it into the layout node traversal + layout startup.
• Expose the new signal via types (AgenticBrowserSignal enum + Constant.AgenticBrowserSignal = "<!>ABS").
• Add a Playwright test suite covering initial, dynamic, transient, shadow DOM, and iframe scenarios; bump package versions to 0.8.70.

Reviewed changes

Copilot reviewed 12 out of 13 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
test/agentic-browser.test.ts	Adds Playwright coverage for the new agentic marker variable emission behavior.
packages/clarity-visualize/package.json	Bumps package and dependency versions to 0.8.70.
packages/clarity-js/types/data.d.ts	Adds AgenticBrowserSignal enum and <!>ABS constant key to the public type surface.
packages/clarity-js/src/layout/node.ts	Hooks marker detection into element processing during layout traversal.
packages/clarity-js/src/layout/index.ts	Resets agentic marker state during layout startup.
packages/clarity-js/src/layout/agent.ts	Implements exact-id marker identification and per-page deduped variable emission.
packages/clarity-js/src/core/version.ts	Bumps clarity-js internal version string to 0.8.70.
packages/clarity-js/package.json	Bumps package version to 0.8.70.
packages/clarity-devtools/static/manifest.json	Bumps extension manifest version/version_name to 0.8.70.
packages/clarity-devtools/package.json	Bumps package and dependency versions to 0.8.70.
packages/clarity-decode/package.json	Bumps package and dependency versions to 0.8.70.
package.json	Bumps root monorepo version to 0.8.70.
lerna.json	Bumps Lerna version to 0.8.70.

[shawj0]

This callback runs inside an injected HTML <script> as plain JavaScript, so a TypeScript annotation would be invalid here. This matches existing test patterns; no change needed.