* Add iframe support for CLI interactions and snapshots
This PR adds comprehensive iframe support to the agent browser CLI, allowing users to interact with elements inside iframes seamlessly.
## Problem
Users couldn't interact with elements inside iframes via the command line. The existing `frame` command was non-functional as it set `active_frame_id` but no other code read this value.
## Changes Made
### Enhanced Frame Context Tracking
- Added `frame_id` field to `RefEntry` to track which frame each element reference belongs to
- Updated `RefMap::add` and related methods to accept and store frame context
- Modified element resolution functions to use frame context from ref entries
### Improved Frame Command
- Fixed the existing `frame` command to actually work by threading `active_frame_id` through snapshot operations
- Added support for iframe element references (e.g., `frame @e2`) in addition to CSS selectors
- Enhanced frame detection to work with both named frames and iframe elements
### Updated Snapshot Behavior
- Modified `take_snapshot` to accept optional frame context parameter
- Updated all snapshot call sites to pass appropriate frame context
- Maintained backward compatibility while enabling frame-scoped operations
### Element Resolution Updates
- Updated `resolve_element_center` and `resolve_element_object_id` to use frame context from ref entries
- Modified `find_node_id_by_role_name` to support frame-specific element lookup
- Ensured all interaction functions work correctly within iframe contexts
## Implementation Details
- Frame context is now properly propagated through the entire element interaction pipeline
- The `frame` command can accept both CSS selectors and element references
- All existing functionality remains intact while adding iframe capabilities
- Added `Iframe` to interactive roles for better element discovery
Fixes#863
* docs: add iframe support documentation
Document the new iframe capabilities across all documentation surfaces:
- Auto-inlining of iframe content in snapshots
- Direct interaction with iframe element refs
- frame command support for element refs (@e3)
- Scoped snapshots via frame switching
* fix: pass active frame context to diff snapshots and fix nameless iframe lookup
- handle_diff_snapshot now respects active_frame_id instead of always
passing None, so diff snapshots work correctly inside iframes
- Nameless/id-less iframes now fall back to src URL (or null) instead of
the literal string 'frame' which never matched any frame in the tree
* fix: resolve iframe frame ID via DOM.describeNode and reduce code duplication
- handle_frame: Use DOM.describeNode + contentDocument.frameId to resolve
iframe frame IDs directly, fixing failures for nameless iframes that
lack name/id/src attributes
- element.rs: Deduplicate add() by delegating to add_with_frame()
- snapshot.rs: Guard against out-of-bounds insert_str when iframe marker
is on the last line without a trailing newline
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Co-authored-by: ctate <366502+ctate@users.noreply.github.com>
