fix: Claude multiline suggestion placement

[akramj13]

Summary

• Correct Claude Desktop multiline ghost-text placement by detecting AXStaticText frames that span multiple visual lines.
• Prefer exact previous-character AX bounds for wrapped runs, with TextKit layout estimation as a fallback.
• Preserve the fast path for true single-line runs and avoid redundant descendant searches.
• Restore fade-in settings initialization required for Cotabby Dev builds and add the project-local build/run action.

Root cause

Claude's Electron accessibility tree exposes a wrapped prompt as one AXStaticText frame. Cotabby treated that union rectangle as a single line and placed the caret proportionally inside it. Near the right edge, the overlay wrapped to the next line's left edge and covered existing text.

Validation

• Cotabby Dev Debug build completed with code signing disabled and launched with -cotabby-debug.
• Focused Xcode tests passed for caret run placement, focus selection, layout repair, text-layout estimation, AX geometry, throttle caching, and settings initialization.
• Live Claude verification resolved wrapped runs through exact character bounds or the layout fallback instead of the single-line aligned-run path.
• git diff --check passed.

Linked issues

solves #754

Risk / rollout notes

• The additional AX bounds query runs only for ambiguous wrapped runs carrying the active selection.
• Ordinary per-line static text runs remain on the existing measured fast path.

Greptile Summary

This PR fixes misplaced Claude Desktop ghost-text by detecting AXStaticText nodes whose frame is the union of multiple soft-wrapped lines rather than a single rendered line, then recovering the true caret position from either exact previous-character AX bounds or a TextKit layout estimate as a fallback.

• Introduces canUseProportionalCaretPlacement to classify wrapped-union frames; adds allowsProportionalCaretPlacement and caretCharacterFrame to the TextRun cache so the expensive AppKit measurement and the per-character AX query happen only once per throttle window instead of on every caret poll.
• Adds resolveWrappedRunCaret to handle the ambiguous-frame path separately, and threads allowsDeepSearch: false through CaretGeometryResult → AXFocusCandidate → CaretGeometrySelector.shouldSearchDeep to prevent the deep BFS from redundantly re-discovering the same union rect on every poll tick.
• Restores two missing fadeIn* field assignments in SuggestionSettingsModel.applyData, adds the build_and_run.sh helper with a retry-polling launch-verify function, and expands test coverage with captured real-world Claude frames.

Confidence Score: 5/5

Safe to merge — all changed paths are well-guarded, the new wrapped-run detection is conservative by design, and the fix is covered by real captured-frame regression tests.

The classification heuristic intentionally favors false negatives over false positives, so the worst outcome of a misclassification is an extra IPC round-trip rather than misplaced ghost text. The allowsDeepSearch: false guard is threaded end-to-end without any gap. No existing behavior is removed — the single-line proportional path is preserved as the fast default.

No files require special attention.

Important Files Changed

Filename	Overview
Cotabby/Services/Focus/AXTextGeometryResolver.swift	Core change: adds wrapped-run detection via canUseProportionalCaretPlacement, early-exits to resolveWrappedRunCaret when the selected run is ambiguous, and refactors metrics to use only single-line runs. The selectedRun.frame direct access avoids the index-mismatch that would have occurred had cocoaRunFrames[placement.runIndex] been kept after filtering to measurableRuns.
Cotabby/Services/Focus/StaticTextRunWalkThrottle.swift	Promotes TextRun from a named tuple to a proper struct, adding caretCharacterFrame and allowsProportionalCaretPlacement fields. The init with a nil default for the optional character frame preserves backward compatibility.
Cotabby/Support/CaretGeometrySelector.swift	Adds primaryAllowsDeepSearch guard as the first check in shouldSearchDeep, short-circuiting to false before any quality evaluation. Default true preserves behavior for all existing callers.
Cotabby/Services/Focus/FocusSnapshotResolver.swift	Threads caretAllowsDeepSearch from CaretGeometryResult through AXFocusCandidate to shouldSearchDeep. The ?? true default for nil results correctly preserves the "try deep search when no primary result exists" path.
Cotabby/Models/SuggestionSettingsModel.swift	Adds two previously missing fadeInSuggestions and fadeInDurationSeconds assignments in applyData; a straightforward omission fix.
CotabbyTests/CaretRunPlacementTests.swift	Adds six new tests covering proportional-placement classification using real captured Claude Desktop frames, increasing regression value significantly.
CotabbyTests/StaticTextRunWalkThrottleTests.swift	Updates existing tests to use the new struct-based TextRun init; adds a test verifying that caretCharacterFrame and allowsProportionalCaretPlacement survive the throttle cache window together.
script/build_and_run.sh	New helper script for Cotabby Dev builds with a proper polling loop replacing the prior sleep 1 race condition.
.codex/environments/environment.toml	Registers the new build_and_run.sh as a Codex "Run" action. Autogenerated file, no logic concerns.

_{Reviews (3): Last reviewed commit: "fix: poll for dev app launch" | Re-trigger Greptile}

[akramj13]

@greptileai