Use _get_multi for render state queries and add VT log callback

[dakra]

Summary

• Batch default-color and cursor-style render state queries into ghostty_render_state_get_multi calls (2 keys each), taking advantage of the new batched query API in libghostty
• Add a log callback that routes libghostty internal log messages through the *ghostel-debug* buffer when ghostel-debug-start is active, via ghostty_sys_set(GHOSTTY_SYS_OPT_LOG, callback)
• Fix make build to pass -Doptimize=ReleaseFast -Dcpu=baseline so that make all produces a release binary

Notes

Cell-level and row-level _get_multi batching was explored but reverted:

• FG_COLOR/BG_COLOR return NO_VALUE for default-colored cells, stopping the batch before STYLE is fetched
• ROW_DATA_CELLS populates a pre-allocated handle rather than writing a new one, requiring &term.row_cells instead of a local variable
• Benchmarks showed no measurable performance gain from batching (FFI overhead between statically-linked Zig functions is negligible)
• The render-state-level batches (colors, cursor) are kept as clean groupings of always-succeeding queries

Test plan

• make all passes (105 native tests, 30 evil tests, lint)
• Manual test: ghostel-debug-start, verify VT log messages appear in *ghostel-debug*
• Manual test: verify no performance regression with find or similar rapid-output commands

[Copilot]

Pull request overview

This PR batches select libghostty render-state queries via the new ghostty_render_state_get_multi API, adds a native-module-installed VT log callback that forwards libghostty internal logs into the *ghostel-debug* buffer, and updates build invocations to consistently produce a release binary.

Changes:

• Batch render-state queries for default FG/BG colors and cursor visibility/style using ghostty_render_state_get_multi.
• Add Emacs-native-module functions to enable/disable a libghostty log callback and route messages to ghostel--debug-log-vt.
• Update make build (and align Elisp compilation invocation formatting) to pass -Doptimize=ReleaseFast -Dcpu=baseline.

Reviewed changes

Copilot reviewed 6 out of 6 changed files in this pull request and generated 4 comments.

Show a summary per file

File	Description
src/render.zig	Switches default color and cursor style/visibility queries to batched render-state lookups.
src/module.zig	Adds VT log callback plumbing and exposes ghostel--enable-vt-log / ghostel--disable-vt-log.
src/emacs.zig	Adds cached symbol for ghostel--debug-log-vt used by the native callback.
Makefile	Ensures make build produces a release-optimized baseline CPU build.
ghostel.el	Keeps the Zig build invocation consistent (minor formatting).
ghostel-debug.el	Starts/stops VT log routing when debug logging is enabled/disabled and adds ghostel--debug-log-vt.

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