Add glass row surfaces to plan tree

[NagyVikt]

Summary

• Centralizes ACTIVE NOW and WAVES row rendering through a glass-row helper.
• Keeps row gutters and inter-wave spacing on IOS_BG_GLASS with IOS_HAIRLINE dividers instead of blank dead rows.
• Adds a regression test for wave-level spacing using glass hairlines.

Verification

running 8 tests
test claim_map_tests::assignment_lines_use_real_rollup_when_no_claims ... ok
test claim_map_tests::assignment_lines_group_claimed_tasks_by_agent ... ok
test claim_map_tests::active_now_rows_use_glass_surface_and_hairline ... ok
test spotlight_tests::spotlight_catalogue_matches_watcher_order ... ok
test claim_map_tests::wave_rows_use_glass_surface_and_hairline ... ok
test claim_map_tests::wave_level_spacing_uses_glass_hairline_not_dead_air ... ok
test claim_map_tests::waves_render_includes_claim_map_section ... ok
test spotlight_tests::spotlight_open_and_close_reset_state ... ok

test result: ok. 8 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out; finished in 0.01s