fix(editor): favorite keyword autocomplete, Cmd+D shortcut, and selectable Details fields

[datlechin]

Three fixes from v0.47.0 feedback. Each goes at the root cause.

1. Field names in the Details panel are selectable

The row Details panel rendered the column name as a plain Text, which has no selection. Added the native .textSelection(.enabled) to the field header, so both the field name and the type badge can be selected and copied (double-click a word, ⌘C, right-click Copy). Scoped to this panel; the shared TypeBadge component is untouched.

2. Save as Favorite shortcut works again (Cmd+D) + toolbar button

0.47.0 moved the shortcut from Cmd+D to Control-Command-D to leave Cmd+D for the "Don't Save" sheet. But Control-Command-D is the macOS system "Look Up" shortcut, so the system swallowed it and the shortcut never fired (right-click still worked).

• Default is back to Cmd+D, the standard bookmark/favorite idiom. It fires reliably, and it coexists with the modal "Don't Save" sheet the same way Safari does (the sheet's Cmd+D only applies while that sheet is open).
• Added Control-Command-D to the system-reserved list so the settings conflict checker warns anyone who picks it.
• Added a star button to the editor toolbar (reuses the existing save-favorite path, disabled when the query is empty), so favoriting is discoverable without the keyboard.

3. Favorite keyword expansion shows in autocomplete

A saved favorite's keyword was supposed to surface as an autocomplete suggestion, but never appeared. Root cause: in SQLCompletionProvider.getCandidates, favorites were appended at the top of the function, then discarded by the items = ... reassignment in most clause branches, including the .unknown branch that handles the start of a statement (the natural place to type a keyword).

Moved favorite injection into a favoriteCompletions(matching:) helper appended after the clause switch, so it survives every branch. The early-return dot-prefix path keeps favorites out of table.column completion. .favorite already ranks first, so the suggestion appears at the top of the popup with the favorite's name as its detail.

Tests

• SQLCompletionProviderTests: keyword expands at statement start, survives clause rebuild, is excluded after a dot prefix, and requires a prefix match.
• KeyboardShortcutTests: Cmd+D is the Save as Favorite default, Control-Command-D is system-reserved, and no default shortcut collides with a reserved combo.

Docs / changelog

• docs/features/favorites.mdx and docs/features/keyboard-shortcuts.mdx updated for the new shortcut, the toolbar button, and clearer keyword usage.
• CHANGELOG.md Unreleased: Added (toolbar button, selectable Details fields), Changed (Cmd+D), Fixed (keyword autocomplete).

Production files pass swiftlint lint --strict. The user builds in Xcode.