Feature Request: Configurable filename pattern for saved images

[stefnw]

Summary

Add a configurable filename pattern setting for saved images, replacing
the current behavior of deriving filenames from the positive prompt.

Problem

Currently, Draw Things generates filenames for saved images based on the
positive prompt text. This causes several practical issues:

1. Similar prompts produce near-identical filenames, making it hard to
   distinguish or sort generations from the same session.
2. Filenames don't sort chronologically in Finder/Files, since prompt
   text has no temporal component.
3. Special characters in prompts (commas, parentheses, quotes) may be
   stripped or replaced inconsistently, breaking external tooling that
   parses filenames.
4. External pipelines (batch processing, asset management, sync tools)
   need predictable filename schemes, not human-readable prompts.

Proposed Solution

Add a new setting under Settings → Save Generated Image To (or a similar
location) called "Filename Pattern", accepting a template string with
placeholder tokens.

Suggested tokens

Token	Resolves to
{datetime}	20260504-143052 (YYYYMMDD-HHMMSS)
{date}	20260504
{time}	143052
{seed}	The seed value used
{model}	Short model identifier (e.g. flux1-dev)
{lora}	Active LoRA name (or empty if none)
{steps}	Step count
{sampler}	Sampler name
{prompt:N}	First N characters of the prompt (sanitized)
{counter}	Auto-incrementing counter per session
{project}	Current project name

Example patterns

{datetime}{seed}.png
→ 20260504-143052_3847291038.png
{date}{project}{counter:03}.png
→ 20260504_portrait-shoot_001.png
{datetime}{model}{seed}{prompt:40}.png
→ 20260504-143052_flux1-dev_3847291038_portrait-photo-soft-windo.png

Default behavior

The default pattern should preserve current behavior for backward
compatibility, e.g. {prompt:100}.png.

Use Case

I'm using Draw Things for batch image generation (50+ images per session)
involving LoRA-based character workflows and prompt variations. Predictable,
chronologically sortable filenames are essential for:

• Organizing generations in Finder/Files
• Feeding output into downstream tools (image organizers, photo libraries)
• Maintaining clear provenance (which seed, which model, which session)
• Avoiding filename collisions across similar prompts

Additional Notes

• Pattern validation should warn users about invalid characters for the
  target filesystem (/, \, :, *, ?, ", <, >, | on most
  platforms).
• A "Reset to default" button next to the pattern field would help users
  recover from misconfiguration.
• Optional: a small live preview showing how a sample filename would look
  with the current pattern.

Thanks for considering — Draw Things is the most polished local generation
app on macOS/iOS, and this would be a small but meaningful quality-of-life
improvement for power users and batch workflows.

[dwt]

This would also be really useful for draw-things-cli, something like image-title-{counter}.png would be super helpful