feat(files): file browser redesign on PC and phone, and RemEx 3.1.0 (versionCode 39)

Directory.Build.props

@@ -1,6 +1,6 @@
 <Project>
   <PropertyGroup>
-    <Version>3.0.0</Version>
+    <Version>3.1.0</Version>
     <Authors>Connor Lindsay</Authors>
     <Company>CLindsay94</Company>
     <NoWarn>$(NoWarn);CA1416;CS0067;CS1591;CS1573</NoWarn>

README.md

@@ -1,6 +1,6 @@
 <div align="center">
 
-<img src="docs/assets/remex-banner.svg" alt="RemEx 3.0: remote control for your PC, from your phone" width="100%" />
+<img src="docs/assets/remex-banner.svg" alt="RemEx 3.1: remote control for your PC, from your phone" width="100%" />
 
 <br />
 
@@ -14,7 +14,7 @@
 [![Languages](https://img.shields.io/badge/languages-9-8fd694?style=flat-square)](#everything-it-does)
 [![License](https://img.shields.io/github/license/clindsay94/RemEx?style=flat-square)](LICENSE)
 
-**[Get started](#get-started-in-five-minutes)** &nbsp;·&nbsp; **[What's new in 3.0](#whats-new-in-30)** &nbsp;·&nbsp; **[How it works](#how-it-talks-to-your-pc)** &nbsp;·&nbsp; **[Build it](#building-from-source)** &nbsp;·&nbsp; **[Docs](#docs-index)**
+**[Get started](#get-started-in-five-minutes)** &nbsp;·&nbsp; **[What's new in 3.1](#whats-new-in-31)** &nbsp;·&nbsp; **[How it works](#how-it-talks-to-your-pc)** &nbsp;·&nbsp; **[Build it](#building-from-source)** &nbsp;·&nbsp; **[Docs](#docs-index)**
 
 </div>
 
@@ -24,6 +24,55 @@ RemEx runs your PC from your phone over plain LAN: no relay server, no account,
 
 > **3.0 is the biggest release yet.** 296 commits and 1,436 files changed since 2.5.0, a new look shared across both apps, routines that act on their own, and a startup splash that actually shows RemEx finding your PC. It's also the first release in production on Google Play.
 
+## What's new in 3.1
+
+**3.1 redesigns file sharing on both apps.** The PC and the phone now show both devices in one folder tree, preview the file you pick, and show the SHA-256 fingerprint that proves a file arrived exactly as it was sent.
+
+<table>
+<tr>
+<td width="33%" valign="top">
+
+### 🗂️ One tree, both devices
+The PC's File Transfer page and the phone's Files screen list **This PC** (or **This phone**) and the other device side by side. Open folders level by level; the tree follows you as you browse.
+
+</td>
+<td width="33%" valign="top">
+
+### 👁️ Live preview
+Pick a file to see it: photos at full quality with zoom, and text, code and logs in colour with line numbers. Turn on **Live** to follow a log as it grows.
+
+</td>
+<td width="33%" valign="top">
+
+### 🔐 SHA-256 you can see
+Transfers say **Verified** when the fingerprint really matched. Copy a file's fingerprint, compare it with one you paste, or check it against the copy on the other device.
+
+</td>
+</tr>
+<tr>
+<td valign="top">
+
+### ↔️ Send between devices
+**Send to PC** and **Save to phone** into any folder you pick, and on the PC drag files from one device to the other. Everything goes through the same verified transfer queue.
+
+</td>
+<td valign="top">
+
+### 📁 Phone folders you choose
+Add folders from your phone to browse them in RemEx. Your PC only sees one when you turn on **Share with PC**.
+
+</td>
+<td valign="top">
+
+### 📷 Scan to get the phone app
+The PC's Home page shows a QR code that opens RemEx on Google Play.
+
+</td>
+</tr>
+</table>
+
+The full 3.1 write-up is in the [release notes](docs/RELEASE-NOTES-3.1.0.md).
+
 ## What's new in 3.0
 
 <table>
@@ -114,9 +163,9 @@ All four share one shader on Android and the PC, and Original Scan, Cosmic Zoom
 
 | Platform | Download | Size |
 |---|---|---|
-| **Windows** | `RemEx-v3.0.0-Setup.exe` (Inno Setup, installs to run elevated for input and power control) | 55.6 MB |
-| **Android** | `RemEx-V3.0.0-release.apk` (sideload) | 38.2 MB |
-| **Linux x64** | `remex-agent-v3.0.0-linux-x64.tar.gz`, see [Linux install](docs/LINUX_INSTALL.md) | 69.7 MB |
+| **Windows** | `RemEx-v3.1.0-Setup.exe` (Inno Setup, installs to run elevated for input and power control) | — |
+| **Android** | `RemEx-V3.1.0-release.apk` (sideload) | 38.6 MB |
+| **Linux x64** | `remex-agent-v3.1.0-linux-x64.tar.gz`, see [Linux install](docs/LINUX_INSTALL.md) | 70.1 MB |
 
 **Requires:** Android 14 or newer on the phone, a Windows or Linux PC, and both on the same network. To reach your PC from elsewhere, run [Tailscale](https://tailscale.com) on both ends, because RemEx has no relay of its own.
 
@@ -227,6 +276,7 @@ Please don't open a public issue for a vulnerability. See [docs/SECURITY.md](doc
 
 | Doc | What's in it |
 |---|---|
+| [docs/RELEASE-NOTES-3.1.0.md](docs/RELEASE-NOTES-3.1.0.md) | Readable summary of everything in 3.1 |
 | [docs/RELEASE-NOTES-3.0.0.md](docs/RELEASE-NOTES-3.0.0.md) | Readable summary of everything in 3.0 |
 | [docs/CHANGELOG.md](docs/CHANGELOG.md) | Full changelog, all versions |
 | [docs/INSTALL-ANDROID.md](docs/INSTALL-ANDROID.md) | Google Play, sideloading, Auto Blocker, first pairing |

build-remex.ps1

@@ -78,7 +78,7 @@
 .EXAMPLE
     ./build-remex.ps1 -c release -t all
 .EXAMPLE
-    ./build-remex.ps1 -v 3.0.0 -t all -c release
+    ./build-remex.ps1 -v 3.1.0 -t all -c release
 .EXAMPLE
     ./build-remex.ps1 -t windows -NoClean
 .EXAMPLE
@@ -265,6 +265,43 @@ function Sync-DirectoryBuildPropsVersion {
     } else {
         Write-Host "Directory.Build.props is already synced at version $DesiredVersion" -ForegroundColor DarkGray
     }
+
+    Sync-PinnedVersionStrings -RepoRoot (Split-Path -Parent $BuildPropsPath) -DesiredVersion $DesiredVersion
+}
+
+function Sync-PinnedVersionStrings {
+    # The two places that hold the PC version as text rather than reading Directory.Build.props: the Windows
+    # manifest's assemblyIdentity (four parts) and the Inno Setup script's fallback for a bare `iscc` run. Both had
+    # drifted for releases (1.13.0.0 and 2.2.0 at 3.0.0), so every version change now rewrites them too, and
+    # VersionSourceOfTruthTests fails the build if they disagree with Directory.Build.props.
+    param(
+        [Parameter(Mandatory=$true)][string]$RepoRoot,
+        [Parameter(Mandatory=$true)][string]$DesiredVersion
+    )
+
+    $edits = @(
+        @{ Path = Join-Path $RepoRoot "remex.agent/app.manifest"
+           Pattern = '(<assemblyIdentity\s+version=")[^"]*(")'
+           Value = "`${1}$DesiredVersion.0`${2}" },
+        @{ Path = Join-Path $RepoRoot "installer/RemEx.iss"
+           Pattern = '(#define AppVersion ")[^"]*(")'
+           Value = "`${1}$DesiredVersion`${2}" },
+        @{ Path = Join-Path $RepoRoot "installer/RemEx.iss"
+           Pattern = '(iscc /DAppVersion=)[0-9.]+'
+           Value = "`${1}$DesiredVersion" }
+    )
+    foreach ($edit in $edits) {
+        if (-not (Test-Path $edit.Path)) {
+            Write-Warning "$($edit.Path) not found; its version was left as it was."
+            continue
+        }
+        $text = Get-Content $edit.Path -Raw
+        $updated = [regex]::Replace($text, $edit.Pattern, $edit.Value)
+        if ($text -ne $updated) {
+            Set-Content $edit.Path $updated -NoNewline
+            Write-Host "  Updated the version in $(Split-Path -Leaf $edit.Path) to $DesiredVersion" -ForegroundColor Green
+        }
+    }
 }
 
 # Force output to support emojis/colored text on Windows PowerShell
@@ -646,7 +683,7 @@ Sync-DirectoryBuildPropsVersion -BuildPropsPath $BuildPropsPath -DesiredVersion
 # 5. Restore .NET Solutions
 if ($Target -eq "windows" -or $Target -eq "linux" -or $Target -eq "all") {
     Write-Host "=== Restoring .NET Packages ===" -ForegroundColor Yellow
-    $solutionFile = Join-Paths $RepoRoot "RemEx.sln"
+    $solutionFile = Join-Paths $RepoRoot "Remex.sln"
     dotnet restore $solutionFile
     if ($LASTEXITCODE -ne 0) {
         Write-Error "dotnet restore failed (exit $LASTEXITCODE)"

docs/API_CONTRACTS.md

@@ -115,6 +115,34 @@ same way, so the meaning is fixed:
   listing from the first page (with totals) rather than failing.
 - `nextCursor` is absent on the last page and when the listing was truncated at the total-entry cap.
 
+### Live preview: range reads (`file_read_range_request` / `file_read_range_response`, 2026-10-08)
+Up to 1 MiB (`FileTransferLimits.ReadRangeMaxBytes`) of one file, answered on the control channel in base64 so
+the reply stays well under the 4 MB message limit. Capability-flagged by `fileCapabilities.readRange`.
+
+```jsonc
+// requester → host
+{ "requestId": "…", "rootId": "…", "relativePath": "Logs/app.log",
+  "offset": 0, "length": 1048576,   // 1 … 1 MiB
+  "fromEnd": false }                // true: the LAST `length` bytes (live tail)
+// host → requester
+{ "requestId": "…", "offset": 0, "dataBase64": "…", "fileSize": 52344,
+  "modifiedUtc": 1759900000000, "eof": true, "errorMessage": null }
+```
+
+- Resolved exactly as a download's source is (PC: `ResolvePath` / a consented volume; phone: `facade.resolve`).
+  A directory, a missing file, an unshared root, a negative offset or a length outside 1 … 1 MiB is answered with
+  an `errorMessage`, never silence.
+- An offset at or past the end returns empty `dataBase64` with `eof: true`, not an error: a tail that polls after a
+  truncation sees "nothing new", and `fileSize` going down tells it to start over.
+- The PC opens with `FileShare.ReadWrite | Delete`, so a log another program is still writing can be tailed.
+- The phone answers off its control-message collector and seeks with the provider's file descriptor when it can.
+  A provider that reports size 0 gets `fileSize` = at least what was read.
+- Preview limits shared by both clients: text 2 MiB from the start, or the last 256 KiB when tailing (polled every
+  2 s while visible); images up to 40 MiB, fetched in 1 MiB reads.
+
+`file_hash_request` (existing) is now also answered by the phone (`fileCapabilities.hash`). The wire stays Base64;
+screens show lowercase hex (`HashFormat`, C# and Kotlin twins sharing one set of test vectors).
+
 ### The PC browsing a paired phone (relay, RemEx-xt0af)
 The PC's own File Transfer screen can browse a paired phone. **The connection direction does not
 change**: the phone dials `/ws` and `/ws/files` as always, and the PC opens no socket to it. What is
@@ -124,15 +152,15 @@ them exactly as it would answer any peer. No message type was added.
 
 **Relayed requests (host → phone), and nothing else:** `file_roots_request`, `file_browse_request`,
 `file_volumes_request`, `file_search_request`, `file_manifest_request`, `file_metadata_request`,
-`file_thumbnail_request`, and (RemEx-fgmne) `file_manage_request`. Root management
-(`file_root_manage_request`: which folders the phone shares is only ever the phone's decision), hashing and
-the legacy v2 transfer are refused by the relay before they reach the wire.
+`file_thumbnail_request`, (2026-10-08) `file_read_range_request` and `file_hash_request`, and (RemEx-fgmne)
+`file_manage_request`. Root management (`file_root_manage_request`: which folders the phone shares is only ever
+the phone's decision) and the legacy v2 transfer are refused by the relay before they reach the wire.
 
 Rules the host enforces, each pinned by `PhoneFileRelayTests`:
 - The target must be **paired** (`PairedClientRegistry`) **and connected** on a session that proved its
   identity; otherwise the PC side gets `PhoneNotConnectedException`.
 - A relayed request carries **no `clientId`** (it is nulled on the way out).
-- A reply (`file_*_response` of the eight types above) is accepted only from a session with
+- A reply (`file_*_response` of the ten types above) is accepted only from a session with
   `identityProven && !isLoopback`, only for a request this host sent to **that same client id**, and is
   delivered only to the relay connection that asked. Unrequested replies are dropped; nothing is
   broadcast. Loopback can never answer for a phone (RemEx-4215).
@@ -177,6 +205,15 @@ browsing only while that switch is on. The phone resolves a root id only if it i
   (`IsValidRemoteRelativePath`): the same rules the phone applies. Copy and move are not subject to the 90-second request timeout: they stream the
   whole file on the phone before it answers, so they wait up to 30 minutes.
 
+**Reading a phone's files: live preview and hashing (2026-10-08 redesign).** `file_read_range_request` and
+`file_hash_request` are relayed READ-ONLY. They need nothing from *Let your PC change files*; the phone resolves
+them through the same `facade.resolve` (and so the same `SharedPathPolicy` check against the folders shared right
+now) as a browse, on every request. Before the wire the relay checks the root id, the path
+(`IsValidRemoteRelativePath`, and never the shared folder itself) and, for a range read, the numbers
+(`FileReadRangeValidation`). A hash waits up to 30 minutes (the phone hashes the whole file first); a range read
+keeps the 90-second backstop. The phone advertises both with `fileCapabilities.readRange` / `hash` (additive,
+default false); a PC hides preview and Compute SHA-256 for a phone that does not.
+
 **Folder upload to a phone** is not a new request either: the PC makes each folder with `mkdir`
 (`relativePath` = the parent, `newName` = the folder, shallowest first, a folder that already exists is fine),
 then uploads each file as an ordinary `file_transfer_offer` with `mode: "upload"` into that folder. It is offered