M2 linking actions for headers, rows, and cells

Problem

Define and implement link/action behavior for table headers, rows, and cells including parameter templating and safe fallbacks.

Context

• Table interactions need a consistent action model across headers, rows, and cells without surprising precedence.
• Parameter templating and safe fallback behavior are necessary for real-world drill and navigation use cases.
• This work belongs alongside table schema and formatting docs so interaction rules are explicit and testable.

Possible Solutions

• A - Support cell links only and leave headers and rows non-interactive: low scope, but weak functionality.
• B - Allow arbitrary action config everywhere with minimal validation: flexible, but dangerous and inconsistent.
• C - Recommended: define one action model with scoped attachment points, template substitution, and clear fallback rules when data is missing or invalid.

Plan

1. Enumerate the supported action types and valid targets for each table scope.
2. Define the templating syntax, missing-value handling, and invalid-link behavior.
3. Implement precedence and event behavior across header, row, and cell actions.
4. Add examples and QA cases for drill links, row actions, and failure paths.

Implementation Progress

QA Exploration

• [ ] QA exploration completed (or N/A for non-UI tasks)

Review Feedback

• [ ] Review cleared