[Feature Request] Theme Mode Settings (Light / Dark / OLED / System) + General UX Improvements

[TheDreDay1000]

Overview

First off, great project — the feature density is impressive for a v1.x release,
and the architecture is clean. This issue consolidates a few improvement suggestions
after reviewing the source and README.

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🎨 Theme Mode Settings (Primary Request)

The README explicitly states:

"Forced OLED dark mode across the entire app. No light theme. No theme toggle."

I'd like to request that this be expanded into a proper theme selector. Not everyone
uses their device in dark environments or on OLED panels, and forcing a single theme
limits accessibility and usability for a broad set of users.

Suggested theme options:

Mode	Description
Light	Standard white/light surface Material 3 theme
Dark	Standard Material 3 dark (not pitch black)
OLED / True Black	Current behavior — keep as an option for OLED users
System Default	Follow Android's system-wide dark/light toggle
Material You	Already noted in ROADMAP — dynamic color from wallpaper

I personally prefer Light mode, and the current forced OLED dark makes the app
uncomfortable to use in bright environments. Since the app is already built on
Material 3 + Jetpack Compose, switching between ColorScheme instances at runtime
is relatively straightforward using MaterialTheme with a stored DataStore
preference — which you already use elsewhere in the app.

The ROADMAP mentions "Material You dynamic color option alongside the forced OLED
black" — expanding this into a full theme selector would address that item and this
request together.

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🔐 Security: Cloud Token Persistence

The README notes:

"OAuth tokens are managed in memory. For production, integrate Android Keystore
encryption for persistent token storage."

This is already flagged in the ROADMAP under Safety, but worth reiterating — users
who connect Google Drive, Dropbox, or OneDrive will be re-prompted on every launch.
Keystore-backed token persistence would make the cloud features actually practical
for daily use. This is also listed in the ROADMAP as "Cloud-token re-encryption at
rest."

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📁 File Operations

• Trash / Recycle Bin: Immediate deletion is destructive. A .Trash folder with
  a configurable TTL (already in ROADMAP) would be a major safety net for everyday users.
• Conflict Resolution Dialog: The current fire-and-forget transfer behavior means
  there's no per-file Skip / Replace / Rename / Keep Both control during copy/move
  operations. This is a significant gap for power users managing large file trees.
• Transfer Queue UI: A visible, pausable, reorderable transfer queue with
  per-task progress would bring this up to par with Solid Explorer and MiXplorer.

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🗂️ Navigation & Discovery

• Storage Analyzer / Size Treemap: A DiskUsage-style recursive size breakdown
  is expected in any modern file manager. Great that it's in the ROADMAP — hoping
  it's prioritized early.
• Dual-Pane / Split View: The single biggest UX gap compared to Solid Explorer
  and Total Commander. Also already in ROADMAP — just adding a +1 here.
• Per-Directory View Memory: Remembering grid vs. list and sort order per path
  would make the app feel much more refined for users who organize files differently
  across folders.

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🖥️ UI / UX Polish

• Thumbnail Support for Video / PDF / APK: Currently using Coil for images —
  adding Fetcher/Decoder plugins for video frames (MediaMetadataRetriever),
  PDF pages (PdfRenderer), and APK icons (PackageManager.getPackageArchiveInfo)
  would make the file browser substantially more useful visually.
• Tablet / DeX Layout: A true 3-column layout (tree + list + preview) on large
  screens would be a great addition for power users running Samsung DeX or on tablets.
• Gesture Customization: Swipe actions on list items (already in ROADMAP) —
  quick actions like delete, share, or copy path without long-pressing.

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📦 Distribution

• F-Droid Listing: Already in ROADMAP. Would significantly expand the reach of
  the project among privacy-conscious and open-source users. Please prioritize
  reproducible build metadata for this.

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Summary

Area	Request	In ROADMAP?
Theme	Light / Dark / OLED / System / Material You toggle	Partial
Security	Keystore-backed cloud token persistence	✅ Yes
Files	Trash bin with TTL	✅ Yes
Files	Conflict resolution dialog	✅ Yes
Files	Transfer queue UI	✅ Yes
Navigation	Storage analyzer / treemap	✅ Yes
Navigation	Dual-pane view	✅ Yes
Navigation	Per-directory view memory	✅ Yes
UI	Video / PDF / APK thumbnails	Partial
UI	Tablet / DeX layout	✅ Yes
Distribution	F-Droid listing	✅ Yes

The theme mode request is the most impactful one for me personally — everything
else is already acknowledged in the ROADMAP. Thanks for the great work on this!