feat: Linux desktop app with FUSE mount

.github/workflows/ci.yml

@@ -327,6 +327,45 @@ jobs:
         working-directory: apps/desktop/src-tauri
         run: cargo check --no-default-features --features fuse
 
+  cargo-check-linux:
+    name: Cargo Check (Linux)
+    needs: [changes, lint]
+    if: |
+      !failure() && !cancelled() &&
+      (github.event_name == 'push' || needs.changes.outputs.desktop == 'true')
+    runs-on: ubuntu-22.04
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Install system dependencies
+        run: |
+          sudo apt-get update
+          sudo apt-get install -y \
+            libwebkit2gtk-4.1-dev \
+            libayatana-appindicator3-dev \
+            librsvg2-dev \
+            libssl-dev \
+            libxdo-dev \
+            libfuse3-dev \
+            pkg-config \
+            build-essential
+
+      - name: Install Rust toolchain
+        run: rustup default stable
+
+      - uses: actions/cache@v4
+        with:
+          path: |
+            ~/.cargo/registry
+            ~/.cargo/git
+            apps/desktop/src-tauri/target
+          key: linux-cargo-${{ hashFiles('apps/desktop/src-tauri/Cargo.lock') }}
+          restore-keys: linux-cargo-
+
+      - name: Cargo check with fuse feature
+        working-directory: apps/desktop/src-tauri
+        run: cargo check --no-default-features --features fuse
+
   build-desktop-windows:
     name: Build Windows Desktop
     needs: [changes, cargo-check-windows, typecheck]
@@ -428,3 +467,59 @@ jobs:
           projectPath: apps/desktop
           tauriScript: pnpm tauri
           args: -- --no-default-features --features fuse
+
+  build-desktop-linux:
+    name: Build Linux Desktop
+    needs: [changes, cargo-check-linux, typecheck]
+    if: |
+      !failure() && !cancelled() &&
+      (github.event_name == 'push' || needs.changes.outputs.desktop == 'true')
+    runs-on: ubuntu-22.04
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Install system dependencies
+        run: |
+          sudo apt-get update
+          sudo apt-get install -y \
+            libwebkit2gtk-4.1-dev \
+            libayatana-appindicator3-dev \
+            librsvg2-dev \
+            libssl-dev \
+            libxdo-dev \
+            libfuse3-dev \
+            pkg-config \
+            build-essential
+
+      - name: Install Rust toolchain
+        run: rustup default stable
+
+      - uses: actions/cache@v4
+        with:
+          path: |
+            ~/.cargo/registry
+            ~/.cargo/git
+            apps/desktop/src-tauri/target
+          key: linux-cargo-${{ hashFiles('apps/desktop/src-tauri/Cargo.lock') }}
+          restore-keys: linux-cargo-
+
+      - uses: pnpm/action-setup@v4
+        with:
+          version: 10
+
+      - uses: actions/setup-node@v4
+        with:
+          node-version: '22'
+          cache: 'pnpm'
+
+      - name: Install dependencies
+        run: pnpm install --frozen-lockfile
+
+      - name: Build crypto package
+        run: pnpm --filter @cipherbox/crypto build
+
+      - uses: tauri-apps/tauri-action@v0
+        with:
+          projectPath: apps/desktop
+          tauriScript: pnpm tauri
+          args: -- --no-default-features --features fuse

.planning/REQUIREMENTS.md

@@ -142,7 +142,7 @@ Requirements for production release. Each maps to roadmap phases 12+.
 
 ### Cross-Platform Desktop
 
-- [ ] **PLAT-01**: Linux desktop app (Tauri + AppImage/deb, FUSE mount via libfuse)
+- [x] **PLAT-01**: Linux desktop app (Tauri + AppImage/deb, FUSE mount via libfuse)
 - [x] **PLAT-02**: Windows desktop app (Tauri + MSI/NSIS, virtual drive via WinFsp/Dokany)
 
 ### Cross-Platform E2E Testing
@@ -363,7 +363,7 @@ Which phases cover which requirements. Updated during roadmap creation.
 | SYNC-05     | Phase 16   | Pending  |
 | SYNC-06     | Phase 16   | Pending  |
 | TEE-06      | Phase 17   | Pending  |
-| PLAT-01     | Phase 11.3 | Pending  |
+| PLAT-01     | Phase 11.3 | Complete |
 | PLAT-02     | Phase 11   | Complete |
 | E2E-01      | Phase 11.4 | Pending  |
 | E2E-02      | Phase 11.4 | Pending  |

.planning/ROADMAP.md

@@ -48,7 +48,7 @@ See `.planning/archive/m1-ROADMAP.md` for full M1 phase details and plan lists.
 
 - [x] **Phase 11: Windows Desktop** - Windows desktop app with WinFsp virtual filesystem (Tauri + NSIS installer)
 - [x] **Phase 11.1: macOS Desktop Catch-Up** - Close all desktop gaps from Phases 12-12.6 before cross-platform expansion (INSERTED)
-- [ ] **Phase 11.3: Linux Desktop** - Linux desktop app with libfuse FUSE mount (Tauri + AppImage/deb) (INSERTED)
+- [x] **Phase 11.3: Linux Desktop** - Linux desktop app with libfuse FUSE mount (Tauri + AppImage/deb) (INSERTED)
 - [ ] **Phase 11.4: Cross-Platform E2E Testing** - Validate each desktop client against API/web with native Postgres + IPFS per runner (INSERTED)
 - [x] **Phase 12: Core Kit Identity Provider Foundation** - Replace PnP Modal SDK with MPC Core Kit, CipherBox as identity provider
 - [x] **Phase 12.1: AES-CTR Streaming Encryption** - AES-256-CTR for media files with byte-range decryption and in-browser playback (INSERTED)
@@ -105,13 +105,20 @@ Plans:
 **Goal**: CipherBox desktop app runs on Linux with native FUSE filesystem integration via libfuse, full feature parity with macOS and Windows (system tray, credential storage, background sync, auto-start, headless mode)
 **Depends on**: Phase 11 (Windows Desktop — platform abstraction layer reused), Phase 11.1 (macOS catch-up), Phase 11.2 (v1 removal)
 **Requirements**: PLAT-01
-**Research flag**: NEEDS `/gsd:research-phase` -- Linux FUSE (libfuse) packaging differences from macOS fuser, AppImage/deb packaging, Linux system tray (libappindicator vs StatusNotifierItem), Linux keyring (Secret Service API), CI Linux runner requirements
+**Research flag**: COMPLETE -- fuser crate reuse confirmed, Linux mount options/unmount, keyring Secret Service API, Tauri Linux bundling (deb+AppImage), CI system dependencies researched
 **Success Criteria** (what must be TRUE):
 
 1. Linux user can install CipherBox via AppImage or .deb, log in, and access a FUSE mount at ~/CipherBox
 2. Background sync, system tray, and keyring storage work on Linux (parity with macOS/Windows)
 3. CI builds and packages Linux desktop app (adds to existing macOS + Windows matrix)
-   **Plans**: TBD
+
+**Plans:** 3 plans
+
+Plans:
+
+- [x] 11.3-01-PLAN.md — Rust code: Linux cfg gates for mount options, unmount, tray, registry, platform special files + .cargo/config.toml + Cargo.toml keyring feature
+- [x] 11.3-02-PLAN.md — tauri.conf.json Linux bundle config (deb + AppImage) + CI workflow (cargo-check-linux + build-desktop-linux jobs)
+- [x] 11.3-03-PLAN.md — Local build, run, and UAT against staging API (cargo build, FUSE mount, file ops, tray, keyring, sync)
 
 ### Phase 11.4: Cross-Platform E2E Testing (INSERTED)
 
@@ -503,7 +510,7 @@ Parallel phases:
 | 15.1 Client-Side Search     | M2        | 3/3            | Complete    | 2026-02-24 |
 | 16. Advanced Sync           | M2        | 0/TBD          | Not started | -          |
 | 11. Windows Desktop         | M2        | 3/3            | Complete    | 2026-02-22 |
-| 11.3 Linux Desktop          | M2        | 0/TBD          | Not started | -          |
+| 11.3 Linux Desktop          | M2        | 3/3            | Complete    | 2026-02-28 |
 | 11.4 Cross-Platform E2E     | M2        | 0/TBD          | Not started | -          |
 | 17. AWS Nitro TEE           | M2        | 0/TBD          | Not started | -          |
 | 18. Billing Infrastructure  | M3        | 0/TBD          | Not started | -          |

.planning/STATE.md

@@ -5,24 +5,24 @@
 See: .planning/PROJECT.md (updated 2026-02-11)
 
 **Core value:** Zero-knowledge privacy - files encrypted client-side, server never sees plaintext
-**Current focus:** Milestone 2 -- Phase 15.1 COMPLETE (Client-Side Search)
+**Current focus:** Milestone 2 -- Phase 11.3 complete (Linux Desktop)
 
 ## Current Position
 
-Phase: 15.1 (Client-Side Search)
+Phase: 11.3 (Linux Desktop)
 Plan: 3 of 3
 Status: Phase complete
-Last activity: 2026-02-27 -- Started todo: E2E MFA flow test coverage
+Last activity: 2026-02-28 -- Completed 11.3-03-PLAN.md (local build + UAT, 18/18 pass)
 
-Progress: [#########################] (M1 complete, M2 Phase 12 complete, Phase 12.2 complete, Phase 12.3 complete, Phase 12.3.1 complete, Phase 12.4 complete, Phase 12.5 complete, Phase 12.6 complete, Phase 12.1 complete, Phase 11.1: 7/7 COMPLETE, Phase 11.2: 3/3 COMPLETE, Phase 13: 5/5 COMPLETE, Phase 14: 6/6 COMPLETE, Phase 11: 3/3 COMPLETE, Phase 15: 4/4 COMPLETE, Phase 15.1: 3/3 COMPLETE)
+Progress: [#########################] (M1 complete, M2 Phase 12 complete, Phase 12.2 complete, Phase 12.3 complete, Phase 12.3.1 complete, Phase 12.4 complete, Phase 12.5 complete, Phase 12.6 complete, Phase 12.1 complete, Phase 11.1: 7/7 COMPLETE, Phase 11.2: 3/3 COMPLETE, Phase 13: 5/5 COMPLETE, Phase 14: 6/6 COMPLETE, Phase 11: 3/3 COMPLETE, Phase 15: 4/4 COMPLETE, Phase 15.1: 3/3 COMPLETE, Phase 11.3: 3/3 COMPLETE)
 
 ## Performance Metrics
 
 **Velocity:**
 
-- Total plans completed: 137
-- Average duration: 5.5 min
-- Total execution time: 13.3 hours
+- Total plans completed: 138
+- Average duration: 5.6 min
+- Total execution time: 15.0 hours
 
 **By Phase (M1 summary):**
 
@@ -44,10 +44,11 @@ Progress: [#########################] (M1 complete, M2 Phase 12 complete, Phase
 | M2 Phase 11     | 3/3   | 35 min  | 11.7 min |
 | M2 Phase 15     | 4/4   | 35 min  | 8.8 min  |
 | M2 Phase 15.1   | 3/3   | 17 min  | 5.7 min  |
+| M2 Phase 11.3   | 3/3   | 104 min | 34.7 min |
 
 **Recent Trend:**
 
-- Last 5 plans: 7m, 4m, 8m, 5m, 2m
+- Last 5 plans: 8m, 5m, 12m, 2m, 90m
 - Trend: Stable
 
 Updated after each plan completion.
@@ -211,6 +212,11 @@ Recent decisions affecting current work:
 | Module-level callback for cross-component search rebuild               | 15.1-02   | registerRebuildCallback/triggerSearchIndexRebuild avoids prop drilling from AppShell to FileBrowser                  |
 | Auth state transition watcher for search index cleanup                 | 15.1-02   | useRef tracks prev isAuthenticated; true->false triggers clearIndex; self-contained in useSearch hook                |
 | Unicode file type icons in search results                              | 15.1-02   | Terminal aesthetic consistency; no additional icon library needed                                                    |
+| WinFsp resource glob left as-is for Linux builds                       | 11.3-02   | Placeholder MSI tracked in git; glob matches harmlessly on all platforms                                             |
+| ubuntu-22.04 pinned for Linux CI (not ubuntu-latest)                   | 11.3-02   | Ensures glibc 2.35 compatibility; prevents drift to 24.04                                                            |
+| AutoUnmount removed from Linux mount options                           | 11.3-03   | Requires user_allow_other in /etc/fuse.conf; explicit fusermount3 -u is more portable                                |
+| FOPEN_DIRECT_IO + write_generation for O_TRUNC race                    | 11.3-03   | Linux kernel page cache causes stale reads after truncation; DIRECT_IO bypasses cache for written files              |
+| Green tray icon for Linux, icon_as_template macOS-only                 | 11.3-03   | Black template icons invisible on dark panels; macOS tinting does not work on Linux                                  |
 
 ### Pending Todos
 
@@ -283,16 +289,17 @@ Recent decisions affecting current work:
 - Phase 12.5 (MFA Polishing, UAT & E2E): COMPLETE -- all 3 plans done (SecurityTab wiring, wallet E2E tests, UAT final verification)
 - Phase 12.6 (Per-File IPNS Metadata): COMPLETE -- all 5 plans done (crypto primitives, batch publish backend, frontend service layer, hooks & components, recovery tool + docs)
 - Phase 13 (File Versioning): COMPLETE -- all 5 plans done (version entry types, creation service, desktop FUSE, version history UI, recovery tool + build verification)
+- Phase 11.3 (Linux Desktop): COMPLETE -- 3/3 plans done (Rust platform support, packaging & CI, local UAT 18/18 pass)
 - Phase 17 (Nitro TEE): NEEDS `/gsd:research-phase` -- Rust enclave, highest risk item
 
 ## Session Continuity
 
-Last session: 2026-02-26
-Stopped at: Completed quick task 022 (Fix MFA status detection false positive)
+Last session: 2026-02-28
+Stopped at: Completed 11.3-03-PLAN.md (Linux UAT 18/18 pass, Phase 11.3 complete)
 Resume file: None
-Next: Quick task 022 complete. Next phase TBD.
+Next: All three desktop platforms validated (macOS, Windows, Linux). Ready for next phase.
 
 ---
 
 _State initialized: 2026-01-20_
-_Last updated: 2026-02-26 after quick task 022 complete (Fix MFA status detection false positive)_
+_Last updated: 2026-02-28 after Phase 11.3 Plan 03 complete (Linux Local Build & UAT)_