Add conversation caching, session organization, and file management

README.md

@@ -70,6 +70,151 @@ release APK.
 For a server on the same local network, a URL might look like
 `http://192.168.1.10:3080`.
 
+## Conversation history loading
+
+The conversation screen initially requests the latest **five user rounds**. A
+round includes the prompt, thinking, tool calls/results and the assistant reply;
+an unfinished latest round counts too. Scrolling near the top loads five earlier
+rounds, with a retry button on failure. Replies exceeding 500 underlying records
+are split across pages so one long round cannot expand into an unbounded fetch.
+
+Deploy the accompanying Codeg server changes for `tailRounds` / `roundLimit`
+support. Existing server clients remain compatible. An older server may return
+the full transcript; Android accepts that response and disables history paging
+when window metadata is absent. Servers supporting only record paging use a
+30-record fallback for older pages.
+
+History pages are verified against the loaded prefix fingerprint. Completion
+and reconnect refreshes preserve the already-loaded window; incompatible
+history is reset to a fresh recent window. Session-wide usage statistics remain
+session-wide regardless of the loaded range.
+
+Debug builds emit `CodegTranscript` timing logs for detail/history downloads,
+decoded payload bytes (before HTTP compression), JSON decoding, and persisted
+timeline conversion. On a device, compare the same long session and network
+conditions before/after the change, including first entry, upward pagination,
+and a completed live reply. Also verify reading position, retry after a network
+failure, and a round spanning multiple history pages. Release builds omit these
+logs, and neither build logs transcript content through this instrumentation.
+
+## Local conversation cache
+
+Saved server profiles cache the conversation list (with folder/grouping context)
+and confirmed transcript pages in the app's private cache directory. On entry,
+cached data appears first. Idle snapshots younger than 60 seconds avoid another
+fetch; older snapshots refresh in the background. Live sessions always check the
+server and reattach. Network failures keep cached content visible with a retry.
+
+Use the list's refresh button/pull gesture or **Refresh** in a conversation's
+overflow menu to bypass freshness. Conversation refreshes retain the loaded
+history window and leave the composer and live stream intact. During a live
+reply, transcript replacement waits for completion so the response is not shown
+twice. Live/optimistic messages and interactive approval cards are not cached;
+the last confirmed snapshot stays readable until a completed response replaces it.
+
+Reopening a cached conversation decodes just its latest five-round/500-record
+page. Loaded older pages are available offline while retained in the same
+snapshot. An authoritative detail refresh replaces that snapshot: structural
+prefix hashes do not prove message text equality, so unrefreshed older cached
+pages are discarded. Old servers without window metadata retain their existing
+full-history fallback.
+
+Cache keys separate profiles, normalized server URLs and credentials; tokens
+and URLs are not written into cache filenames. Changing an endpoint/token or
+removing a profile clears its cache. Conversation mutations invalidate the
+affected detail and list; starting a reply marks the last confirmed detail stale.
+Clearing/deleting snapshots fences requests already in flight against writing
+them back.
+
+**Settings → Local cache** shows disk usage and clears cached data. The cache
+has a 100 MiB global LRU budget and a 10 MiB payload limit per conversation;
+oversized tails are not stored. It is disposable, excluded from app backups,
+and can also be removed by Android. Clearing it leaves currently displayed
+messages in memory. Unvisited or evicted history still requires the server.
+
+## Conversation file downloads
+
+Open **Files** in a conversation toolbar or **Settings** for the unified file manager.
+**Conversation files** lists files written, modified, or explicitly linked in the
+complete conversation, including history above the phone's loaded message window.
+Files appear before any download. Paths are deduplicated, with the latest operation,
+availability, size and source conversation. Search, switch conversations, or refresh
+manually. The compact index is cached per server and credentials; failed refreshes
+keep the previous list visible. Updated servers use `get_conversation_files`. If an
+older server returns `501 / not_implemented` or an unstructured 404 for that endpoint,
+the file manager reads complete history with the existing conversation API and builds
+the index on the phone. This fallback runs only in the file manager and does not replace
+the paged conversation cache. Large conversations take longer to index on older servers.
+Authentication, permission, and other server errors are reported without triggering fallback.
+Older servers cannot check current file availability in advance; those entries remain
+openable and say that availability is checked on opening. Historical deletion alone does
+not prove that a path is still missing today.
+
+The index recognizes structured write/edit/patch tools and local Markdown
+links, including files built by shell commands when the reply links them. It is not
+a filesystem change monitor: arbitrary shell side effects, agent tools with no
+recognizable paths, and images embedded without a local file URI cannot be indexed.
+It records file paths rather than historical versions; previews show current files.
+
+Tap **View** to preview a server file without saving it in Downloads. Tap **Save to
+phone** to start a persistent download. Non-APK Markdown file links also open a remote
+viewer directly; APK links retain the direct download/install flow. Absolute paths are server
+paths, including files outside registered projects such as the server's Downloads
+folder. The server validates access to the explicitly linked file through the
+authenticated ticket endpoint. Relative paths stay within the conversation folder.
+Paths containing spaces can use Markdown angle brackets,
+for example `[Download APK](</workspace/Android Project/app-debug.apk>)`.
+
+The app uses the server's authenticated `workspace_download_ticket` endpoint and
+hands the one-use URL to Android DownloadManager. The server token is never sent
+to the system downloader. No third-party hosting service or separate file server
+is needed. The connected Codeg server must support workspace download tickets.
+
+Select the **Download history** tab in the file manager for the independent
+download list. It shows records for the selected saved server and
+endpoint, with progress, refresh, retry, cancel, file viewing and a source
+conversation shortcut. Records survive app restarts. Removing a history entry
+does not delete the file. Files downloaded by older versions without persistent
+history remain in the phone's system Downloads folder.
+
+Android saves files under **Download/Codeg**, using unique names to preserve
+existing files. Multiple transfers can continue through the system downloader
+after leaving the conversation. Retry starts a new transfer with a fresh ticket;
+interrupted one-use transfers cannot reliably resume. The list opens saved copies;
+tapping **Save to phone**, an APK link, or the local viewer's **Download again** fetches the
+current server file, so a new APK at the same path does not reopen an older build.
+Earlier completed files remain intact. If a saved file is missing, retry downloads
+a new copy.
+
+Files open a separate viewer. Images support pinch zoom, pan and double tap
+zoom/reset; text and code support selection and copy. Viewing is offline after
+the download completes. Images are decoded off the main thread and limited to
+2048 pixels per side; remote image transfer is limited to 12 MiB, with download
+offered for larger images. Text preview is limited to 128 KiB or 2000 lines, with a
+visible truncation notice; copying copies that preview. The complete download
+remains unchanged. HTML is displayed as source; PDF, SVG, archives and other
+unsupported formats use external apps. Returning to the source conversation
+preserves its ViewModel, draft and scroll position.
+
+APK installation from the viewer opens Android's installer. If needed, allow installs from Codeg
+in system settings, then return and tap **Install** again. Ordinary web links open
+the browser; direct HTTP(S) APK links use the same download flow without sending
+Codeg credentials. Existing older Android builds need this version installed first
+before their conversation links can use this feature.
+
+## Hide folders on this device
+
+Use a folder row's overflow menu in **Folders**, or a project group's menu in
+**Chats**, to choose **Hide on this device**. The folder and its worktrees are
+removed from the project list, ordinary conversation groups and Recent. Pinned
+conversations, global search and pages already open remain accessible.
+
+Both lists offer **Show hidden folders** in their toolbar menus, with a Restore
+button for each hidden folder. Choices survive app restarts and are isolated by
+saved server profile and URL. They do not close the server workspace, change
+other clients, remove files or delete conversations. Clearing conversation cache
+does not reset these preferences.
+
 ## Security model
 
 Server tokens are encrypted with AES-256-GCM using a key held by the Android

app/build.gradle.kts

@@ -64,6 +64,7 @@ android {
     buildTypes {
         debug {
             applicationIdSuffix = ".debug"
+            versionNameSuffix = "-debug.${providers.gradleProperty("debugBuildTag").getOrElse("local")}"
             isDebuggable = true
         }
         release {

app/src/debug/res/values-zh-rCN/strings.xml

@@ -0,0 +1,3 @@
+<resources>
+    <string name="app_name">Codeg Debug</string>
+</resources>

app/src/debug/res/values/strings.xml

@@ -0,0 +1,3 @@
+<resources>
+    <string name="app_name">Codeg Debug</string>
+</resources>

app/src/main/AndroidManifest.xml

@@ -3,6 +3,7 @@
 
     <uses-permission android:name="android.permission.INTERNET" />
     <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
+    <uses-permission android:name="android.permission.REQUEST_INSTALL_PACKAGES" />
 
     <application
         android:name=".CodegApplication"