Integrates canonical `main` @ 2625ec7 after PR #137 (tab-width parity)
merged. The agreed order was #137 first, this lane second: #137 was
approved and FROZEN at 5b23e11, and "frozen" is incompatible with
"rebase onto the resulting main" — landing it second would have broken
its freeze and voided its approval.
Integrated by MERGING main into the branch rather than rebasing, matching
repo precedent (Merge canonical main into vterm-tui, ... into modeline
detection). A rebase would have force-pushed away the review anchors on
the two completed review rounds of #135.
Main had also moved past this lane's base by #133/#134/#136, so the
integration surface was wider than the #135/#137 overlap: src/
semantic_render.rs was a fourth overlapping code file. It auto-merged, as
did pmacs-protocol/src/lib.rs. The single code conflict was the
pmacs_protocol import list in pmacs-gpu/src/main.rs — TAB_STOP_COLUMNS
against the terminal types — resolved as a union.
The feared semantic collision did not occur, and this is verified rather
than assumed: terminal cell geometry still uses the monospace advance and
never TAB_STOP_COLUMNS. pmacs-gpu/src/terminal.rs references neither the
constant nor display_width, and terminal_cell_viewport / terminal_run_rect
/ hit_test_cell derive from mono_advance() and code_line_height() alone.
That separation is correct by construction: a terminal's columns come
from the child, while tab expansion is a document projection concern.
Doc conflicts resolved toward landed state: the tab-width lane moves to
"Closed since the last snapshot", the #135/#137 coordination section is
kept as a resolved worked example, and the Arc 5 lines in the roadmap and
handoff now read "implemented and in review". While resolving, restored a
clause main had dropped from the handoff's injection-follow-ups list
("literals, doc-comment code);"), keeping main's strikethrough-and-SHIPPED
convention for the modeline entry.
Post-integration gates, from a clean tree: cargo fmt --check; strict
workspace clippy; pmacs-protocol 17; cargo test --lib 1,768; --features
crdt 1,944 (3 ignored each); vterm Stage 1 9/10, Stage 2 4/4, Stage 3
5/7, statusline 7/8, tab-width 2/2 (default/CRDT); M4 121 passed (3
ignored, 1 filtered); required GPU 139; workspace sweep 2,946 passed
across 84 suites (19 ignored), one invocation; git diff --check clean.