Adds theme-aware v1 builders for icon_button, image_placeholder,
inbox_message, inline_action, input_with_action, invite_row, kbd,
legend_item, link, and list_row. Group A (zero-color: icon_button,
link, list_row) — no hardcoded colors in v0, all three modes identical.
Group B (kbd) — key bg → surface2, stroke → border in dark/system.
Group C (remaining 6) — surface/text/border/accent/alertColors tokens
applied in dark/system modes, full byte-parity with v0 in light mode.
Extends ext-6 shard (357→647 lines, within 800-line ceiling) housing
all 20 batch-4 + batch-5 tool schema definitions. All 9 touchpoints
wired per playbook: builder, index.ts, pen-core barrel, handler,
dispatcher, ext-6 shard, client shim, server builder, elements.md entries.
Verified: format:check clean, tsc --noEmit clean, 4086/4086 tests pass.