CUBELinux-2: WordFlags/tri-channel 16-bit flag field, tag-14 + scan_by_word_flag, cubetrace capture→replay→golden→lineage, CUBE VP-tree balling index (cubecode::ballindex), cubefs-visible WordFlags, and cube-mvw (sharded multi-writer MVCC store with per-shard WALs + group-commit + compaction, impl CubeBackend => CubeStore<MvwBackend> DB). Adds show-flags/scan-word-flags/trace-*/golden-capture CLI; ~ tests green.

RESUME-20260820-kernel-ready.md

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+# Resume Marker — 2026-08-20
+# Status: kernel ready for compile, workhorse ready for Xfce switching, stopped before heavy build
+
+## What was done this session
+1. **Kernel build environment — READY** (stopped before heavy compile per user request)
+   - Kernel: vanilla v6.19.3 + ipu4 drivers (GRUB entry LOCALVERSION=-ipu4p)
+   - `./check` green, git clean
+   - Rust toolchain: stable 1.97.1 (default) + nightly 1.100.0 installed via rustup
+   - CONFIG_RUST=y set in .config, CONFIG_RUST_IS_AVAILABLE=y
+   - `scripts/target.json` has `rustc-abi: x86-softfloat` (rejected by stable, OK with nightly)
+   - Build fix identified: `RUSTC=/root/.cargo/bin/rustc RUSTLIB_SRC=... make ...` to use nightly
+   - Build NOT started — user wants new session for the heavy compile
+
+2. **GUI session switching — READY** (workhorse has Xfce, GDM shows it)
+   - Xfce 4.20.2 + xfce4-goodies installed on workhorse
+   - `/usr/share/xsessions/xfce.desktop` present, `Exec=startxfce4`
+   - GDM (gdm3) active, shows xfce.desktop + xfce-wayland.desktop at login gear menu
+   - User can switch GNOME↔Xfce at GDM login by clicking gear icon → "Xfce Session"
+   - lightdm package removed (was stuck half-configured; cleaned up via dpkg purge)
+   - No lightdm; gdm3 is the DM; /etc/X11/default-display-manager = /usr/sbin/gdm3
+
+## What remains (for next session / new session)
+- **Kernel compile**: `make -j$(nproc) bzImage modules` with nightly rustc override
+  - Command pattern: `cd /home/CUBELinux/CUBELinux-2/src/CUBELinux-build && RUSTC=/root/.cargo/bin/rustc HOSTRUSTC=/root/.cargo/bin/rustc make -j$(nproc) bzImage modules`
+  - Need to confirm RUST_LIB_SRC path for nightly toolchain
+  - User explicitly asked NOT to auto-launch — new session should decide timing
+- **GRUB**: new entry for -cube kernel; verify ipu4p entry still works
+- **Post-boot verification**: cube fs mount, daemon startup, camera (ipu4) if desired
+
+## Notes
+- User restarted the session; this marker captures where we left off
+- User directive: "get project to point of compiling new kernel, then stop so we can use new session for that"
+- Heavy compile (make -j8) saturates all cores + memory — do NOT start without user go