ROOT CAUSE: src/markdown_table.py:render_table was missing
imgui.table_setup_column() calls. In ImGui, columns MUST be
configured via table_setup_column before table_headers_row is called.
Without it, the table has no defined columns, causing cells to
render at overlapping Y positions. This manifested as text overlap
in the Discussion Hub's read_mode entries (e.g., 'swc2 -> gte_sw'
overlapping the line above it).
FIX: Call imgui.table_setup_column(h, TableColumnFlags_.width_stretch)
for each header BEFORE table_headers_row(). Each column now has a
defined width (stretch = fills available space) and cells render
correctly without overlap.
Tests:
- New test_markdown_table_columns.py asserts setup_column is called
once per column and table_next_column is called for each cell.
- 16/16 broad regression pass (test_markdown_table,
test_markdown_table_render, test_markdown_render_robust,
test_gen_send_empty_context, test_gui_fast_render)
ed