feat: add data-focused UX polish — rich query tables, progress bars, cost badges, schema previews

[anandgupta42]

Add four new TUI components tailored for data engineers:

1. Inline Query Result Tables — Type-aware formatted tables for SQL query
   results with right-aligned numbers, dimmed NULLs, auto-calculated column
   widths that adapt to terminal size, and expand/collapse for large result sets.

2. Query Execution Progress Bar — Live elapsed timer during query execution,
   completion summary with row count + elapsed time + warehouse name, and
   color-coded severity (green < 1s, normal 1-10s, yellow > 10s).

3. Smart Cost Annotations — Inline cost/performance badges on tool calls
   showing row count, elapsed time, truncation status, and warehouse name
   with color-coded severity indicators.

4. Schema-Aware Inline Previews — Rich tree-view schema display with
   short type labels (VARCHAR, INT, TIMESTAMPTZ, etc.), PK/FK detection,
   row count formatting (1.2M, 50.0K), and expand/collapse for wide schemas.

All components:

• Adapt to different terminal widths (tested 20-300 chars)
• Use pure utility functions separated from TSX for testability
• Include 162 tests with 797 assertions covering edge cases,
  screen size matrix, integration pipelines, and error conditions

Also includes GitHub issue template for sparkline sidebar feature.