refactor(memory): complete PMM/VMM/LMM rewrite - bitmap allocators, bug fixes, hardening

PMM Rewrite:
- Replace ~8KB record array with compact bitmaps
  (PhysPresent/PhysAlloc/PhysScanned, 128B each)
- Add PhysOwner[0..1023] for per-block ownership tracking
- new_block: O(1) amortised via NextFreeHint + dword-level BSF scan,
  returns 0 as OOM sentinel
- free_block: O(1) direct bit clear with double-free detection
- alloc_block: validates PhysPresent and PhysAlloc bits before allocation
- Add pmm_free_blocks/pmm_total_blocks stats functions

VMM Correctness Fixes:
- Fix free_page block extraction (Address SHR 10, was using
  raw Address field)
- Fix invlpg operand (use virtual address, was passing PDE index)
- Clear PDE entry on free_page before returning block to PMM
- Remove map_page double-write (delegate to map_page_ex only)
- Add OOM propagation (new_page returns false if PMM returns 0)
- Fix missing pop_trace in new_page error path

LMM Rewrite:
- Replace per-entry record array with bitmap allocator
  (93% vs 43% page efficiency)
- Layout: Header(24B) + Bitmap(64512B) + Padding + Data at 0x10000
- SIZE_PREFIX=16 for 16-byte aligned returns (SSE MOVAPS requirement)
- Next-fit bitmap scan with roving hint (NextFree) and dword-level
  fast skip
- Large alloc sentinel (LARGE_ALLOC_MAGIC=$FFFFFFFE) so kfree detects
  klalloc'd memory
- Implement klfree (was previously a no-op - pages could never
  be returned)
- Implement try_release_page (return fully-free heap pages to VMM/PMM)
- Fix interrupt safety: stack-balanced pushfd/cli/pop +
  restore_if (sti only)
  Fixes Bad TSS caused by popfd restoring dangerous EFLAGS bits (NT, IOPL)
- Zero memory via rep stosd instead of byte-by-byte loop

Hardening:
- kalloc OOM now triggers BSOD instead of returning nil
  (90% of callers don't check)
- Double-free detection in kfree (verify bitmap bits set before clearing)
- Guard bytes ({$IFDEF DEBUG_LMM}): $DEADBEEF sentinel for buffer overrun detection
- kpalloc: bounds check (block >= 1024 -> GPF) + syslog MMIO mapping audit log

Observability:
- Add MEMINFO command as src/prog/meminfo.pas (moved from inline kernel.pas)
- Displays multiboot memory, PMM block stats, LMM heap stats
- Register via progmanager.pas following standard prog pattern

Files changed:
- src/pmemorymanager.pas
- src/vmemorymanager.pas
- src/lmemorymanager.pas
- src/kernel.pas
- src/progmanager.pas
- src/prog/meminfo.pas

compile_lvgl.sh

@@ -1,7 +1,7 @@
 #!/usr/bin/env bash
 # compile_lvgl.sh — Download LVGL v9.2 source and compile into lib/liblvgl.a
 # Clone & compile in /tmp (fast container-local fs).
-# Copy source + objects to /lvgl (host mount) for debugging.
+# Cache liblvgl.a on host mount (/code/lvgl/) to skip rebuild.
 set -e
 
 LVGL_VERSION="v9.2.2"
@@ -10,6 +10,7 @@ LVGL_DIR="/tmp/lvgl"
 OBJ_DIR="/tmp/lvgl_obj"
 CONF_DIR="$(pwd)/lvglh"
 OUT_DIR="$(pwd)/lib"
+CACHE_DIR="/code/lvgl"
 
 CC="gcc"
 CFLAGS="-m32 -march=i686 -ffreestanding \
@@ -26,6 +27,17 @@ echo " "
 echo "Compiling LVGL..."
 echo " "
 
+# If cached liblvgl.a exists on host mount, just copy it and skip everything
+if [ -f "${CACHE_DIR}/liblvgl.a" ]; then
+    echo "Found cached liblvgl.a in ${CACHE_DIR}, copying to ${OUT_DIR}..."
+    cp "${CACHE_DIR}/liblvgl.a" "${OUT_DIR}/liblvgl.a"
+    echo "(Delete lvgl/liblvgl.a to force a full rebuild.)"
+    echo " "
+    echo "LVGL compilation complete (cached)."
+    echo " "
+    exit 0
+fi
+
 # Clone LVGL into /tmp (container-local)
 rm -rf "$LVGL_DIR"
 echo "Downloading LVGL ${LVGL_VERSION}..."
@@ -105,12 +117,14 @@ else
     echo "No custom LVGL files in lvglh/."
 fi
 
-# Copy source + objects to /lvgl host mount for debugging
+# Cache liblvgl.a and source to host mount for next build
-echo "Copying LVGL source and objects to host mount..."
+echo "Caching LVGL to host mount..."
-mkdir /code/lvgl 2>/dev/null || true
+mkdir -p "$CACHE_DIR"
-rm -rf /code/lvgl/* /code/lvgl/.[!.]* /code/lvgl/..?* 2>/dev/null || true
+rm -rf ${CACHE_DIR}/* ${CACHE_DIR}/.[!.]* ${CACHE_DIR}/..?* 2>/dev/null || true
-cp -a "$LVGL_DIR/src" /code/lvgl/src
+cp "${OUT_DIR}/liblvgl.a" "${CACHE_DIR}/liblvgl.a"
-cp -a "$OBJ_DIR" /code/lvgl/obj
+cp -a "$LVGL_DIR/src" "${CACHE_DIR}/src"
+cp -a "$LVGL_DIR"/*.h "${CACHE_DIR}/" 2>/dev/null || true
+cp -a "$OBJ_DIR" "${CACHE_DIR}/obj"
 echo "Done."
 
 echo " "

compile_sources.sh

@@ -4,4 +4,4 @@ echo "======================="
 echo " "
 echo "Compiling FPC Sources..."
 echo " "
-fpc -Aelf -gw -g -gl -n -v0ew -O3 -OpPENTIUM3 -Si -Sc -Sg -Xd -CX -XXs -CfSSE -CfSSE2 -Rintel -Pi386 -Tlinux -FElib/ -Fusrc/* -Fusrc/driver/* -Fusrc/driver/net/* -Fusrc/driver/bus/* -Fusrc/driver/bus/usb/* -Fusrc/driver/hid/* src/kernel.pas
+fpc -Aelf -gw -g -gl -n -v0ew -O3 -OpPENTIUM3 -Si -Sc -Sg -Xd -CX -XXs -CfSSE -CfSSE2 -Rintel -Pi386 -Tlinux -FElib/ -Fusrc/* -Fusrc/include/* -Fusrc/driver/* -Fusrc/driver/net/* -Fusrc/driver/bus/* -Fusrc/driver/bus/usb/* -Fusrc/driver/hid/* src/kernel.pas

src/kernel.pas

@@ -67,7 +67,8 @@ uses
      hashmap, vfs,
      video, vesa, doublebuffer, color, lvgl, desktop, uidebug,
      vterminal,
-     graphicsrefresh, usbhotplug;
+     graphicsrefresh, usbhotplug,
+     fifo, cfifo, cfifols, lifo, circ, minh, maxh, prio;
  
 procedure kmain(mbinfo: Pmultiboot_info_t; mbmagic: uint32); stdcall;
  
@@ -253,6 +254,14 @@ begin
      usbhub.UnitTest;
      usb_keyboard.UnitTest;
      usb_mouse.UnitTest;
+     fifo.UnitTest;
+     cfifo.UnitTest;
+     cfifols.UnitTest;
+     lifo.UnitTest;
+     circ.UnitTest;
+     minh.UnitTest;
+     maxh.UnitTest;
+     prio.UnitTest;
 
      { Register timer-driven tasks }
      graphicsrefresh.init;