feat: option to open pre-populated note editor from Timmy save-as-note actions

[ericfitz]

Investigate whether the "save session as note" and "save message as note" actions in Timmy chat should offer an option to open a pre-populated NoteEditorDialog instead of saving automatically.

Context

Issue #556 implements direct save (no dialog) for both save actions, with a snackbar confirmation. This was chosen for low friction, but there may be cases where users want to review/edit the title or content before saving.

Questions to Investigate

• Do users find the auto-generated titles sufficient, or do they frequently edit them after saving?
• Would a user preference (settings toggle) be appropriate, or should it always be one or the other?
• Should this be a long-press / secondary action, or replace the current behavior entirely?

Depends On

• feat: save Timmy chat sessions and messages as threat model notes #556 (initial save-as-note implementation)