docs: record display-sleep surface spike

[onevcat]

Summary

• record the display-sleep investigation under the existing 063 workflow series
• preserve both spike rounds: Swift-side ordering did not help, while disabling the eager CoreVideo display link proved surface creation itself can work with zero active displays
• record Create Ghostty surfaces while the display is asleep #746 as the final fix: the upstream Ghostty lazy/non-fatal DisplayLink behavior is backported into the pinned GhosttyKit
• withdraw both proposed product fallbacks for this issue: no Prowl-side window-vsync override and no interactive-to-headless/fail policy remain planned
• keep honest ordinary tab/split creation failure propagation only as optional generic hardening, independent of display sleep and R2a
• update the 063 and release ledgers to mark Wire the workflow runner into TCA and the CLI (063 B3) #744 merged and C1 next

Verification

• stable display-off runs used a CoreGraphics/CoreVideo probe (active=0 throughout) and prowl send --capture health checks during the dark interval and after wake
• Create Ghostty surfaces while the display is asleep #746 repeated the same protocol with the rebuilt GhosttyKit: tab, pane, and Profile launches succeeded while dark and recovered DisplayLink after wake
• local Markdown link targets resolve
• git diff --check
• documentation-only correction after the prior make build-app result (0 errors, 0 warnings)

[onevcat]

Second spike round pushed in 9fd061b — it falsifies the first-round conclusion.

• Cause: pinned GhosttyKit v1.3.1 does if (config.vsync) try DisplayLink.createWithActiveCGDisplays() in renderer init; with zero active displays that fails (-6661, logged as error.OutOfMemory) and aborts ghostty_surface_new.
• Verified live: with window-vsync = false the same binary creates working tabs, splits, and Profile panes while dark (shell answers captured inside the display-off interval), and they render after wake. A runtime reload_config toggle is enough; the choice is per surface at creation time.
• Upstream ghostty #13639 (2026-08-05) makes display-link creation lazy and non-fatal; not in a tagged release yet, and the fork cannot currently rebuild GhosttyKit (zig 0.15.2 build runner fails to link under Xcode 26.6).
• Recommendation now: display-aware creation override in Prowl (R2a-sized), typed DISPLAY_UNAVAILABLE, honest tab/split creation, upstream backport later; headless-or-fail policy withdrawn.