#156 Simplify Raycast store package and tooling

Refactors the Raycast extension for a store-focused layout by removing local packaging/build helper scripts, installer artifacts, and generated icon assets, and by dropping pre* npm hooks tied to those workflows. Documentation and changelog now clarify that QuickShell.Suggest.exe is not bundled in this store build and suggestions fall back to local heuristics when unavailable. The code/tests were updated accordingly: removed deprecated exports, switched tests to current APIs, hardened shared-file assumptions for store PR layouts, and fixed a few UI/action and typing details (quick-add action guarding, branch reload action, and path API typing).

[!NOTE]

Remove build tooling and deprecated exports from Raycast store package

• Removes pre-build scripts, environment validation scripts, and the Inno Setup template that were used for sideload/GitHub/WinGet packaging, leaving only npx @raycast/api@latest publish in the publish step.
• Removes deprecated exports COMPANION_PRESETS, WORKSPACE_TERMINAL_CHOICES, TERMINAL_APPLICATION_CHOICES, and resetTerminalCatalogCacheForTests() in favor of their getter-function equivalents.
• Updates discover-git-repos-view to show an 'Adding…' state and ignore duplicate clicks while a repo add is pending.
• Updates set-target-branch-form so the submit action is no longer blocked while branch choices are loading.
• Adjusts suggest-commands warning message to reflect that QuickShell.Suggest.exe is not bundled in the Store build and that local heuristics are used as fallback.

^{Macroscope summarized c052c30.}