feat: kernel memory plugin + unified source menu + driver improvements

- KernelMemory plugin: kernel-mode process/physical memory R/W via IOCTL driver
- rcxdrv.sys: MmCopyMemory for reads, MDL mapping with correct cache types
  (MmCached for RAM, MmNonCached for MMIO only — fixes cache corruption BSOD)
- Driver reconnect: ensureDriverLoaded tries device handle first, no auto
  stop+delete cycle. Manual unload closes handle only, service stays running.
- Unified source menu: ProviderRegistry::populateSourceMenu() shared by both
  main window Data Source menu and RcxEditor inline picker (icons + dll names)
- IProviderPlugin::populatePluginMenu() for conditional plugin actions
  (e.g. "Unload Kernel Driver" only when loaded)
- Physical memory mode removed from selectTarget (access via context menu only)
- requestOpenProviderTab sets base address from provider after template load
- Address parser: vtop(), cr3(), physRead() callbacks for kernel paging expressions

plugins/KernelMemory/linux/rcxkm.c

@@ -0,0 +1,132 @@
+/*
+ * rcxkm.c -- Linux kernel module stub for Reclass kernel memory provider.
+ *
+ * Provides /dev/rcxkm char device with ioctl() dispatch using the same
+ * protocol structs as the Windows driver (rcx_drv_protocol.h).
+ *
+ * Build: make -C /lib/modules/$(uname -r)/build M=$(pwd) modules
+ *
+ * TODO: implement handlers (currently returns -ENOSYS for all IOCTLs).
+ */
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/fs.h>
+#include <linux/miscdevice.h>
+#include <linux/uaccess.h>
+#include <linux/slab.h>
+#include <linux/sched.h>
+#include <linux/pid.h>
+#include <linux/mm.h>
+
+#include "../rcx_drv_protocol.h"
+
+#define DEVICE_NAME "rcxkm"
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Reclass");
+MODULE_DESCRIPTION("Reclass kernel memory provider (stub)");
+
+/* ── IOCTL dispatch ─────────────────────────────────────────────────── */
+
+static long rcxkm_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
+{
+    (void)filp;
+    (void)arg;
+
+    switch (cmd) {
+    case IOCTL_RCX_READ_MEMORY:
+        /* TODO: find_get_pid(pid) -> get_task_struct -> access_process_vm() */
+        return -ENOSYS;
+
+    case IOCTL_RCX_WRITE_MEMORY:
+        /* TODO: access_process_vm() with FOLL_WRITE */
+        return -ENOSYS;
+
+    case IOCTL_RCX_QUERY_REGIONS:
+        /* TODO: walk target mm->mmap via VMA iteration */
+        return -ENOSYS;
+
+    case IOCTL_RCX_QUERY_PEB:
+        /* N/A on Linux (no PEB); could return mm->start_brk or similar */
+        return -ENOSYS;
+
+    case IOCTL_RCX_QUERY_MODULES:
+        /* TODO: walk target /proc/pid/maps or mm VMAs */
+        return -ENOSYS;
+
+    case IOCTL_RCX_QUERY_TEBS:
+        /* N/A on Linux (no TEB) */
+        return -ENOSYS;
+
+    case IOCTL_RCX_PING: {
+        struct RcxDrvPingResponse resp = {
+            .version = RCX_DRV_VERSION,
+            .driverBuild = 1,
+        };
+        if (copy_to_user((void __user *)arg, &resp, sizeof(resp)))
+            return -EFAULT;
+        return 0;
+    }
+
+    case IOCTL_RCX_READ_PHYS:
+        /* TODO: ioremap() + memcpy_fromio() */
+        return -ENOSYS;
+
+    case IOCTL_RCX_WRITE_PHYS:
+        /* TODO: ioremap() + memcpy_toio() */
+        return -ENOSYS;
+
+    default:
+        return -EINVAL;
+    }
+}
+
+/* ── File operations ────────────────────────────────────────────────── */
+
+static int rcxkm_open(struct inode *inode, struct file *filp)
+{
+    (void)inode; (void)filp;
+    return 0;
+}
+
+static int rcxkm_release(struct inode *inode, struct file *filp)
+{
+    (void)inode; (void)filp;
+    return 0;
+}
+
+static const struct file_operations rcxkm_fops = {
+    .owner          = THIS_MODULE,
+    .unlocked_ioctl = rcxkm_ioctl,
+    .open           = rcxkm_open,
+    .release        = rcxkm_release,
+};
+
+static struct miscdevice rcxkm_device = {
+    .minor = MISC_DYNAMIC_MINOR,
+    .name  = DEVICE_NAME,
+    .fops  = &rcxkm_fops,
+};
+
+/* ── Module init/exit ───────────────────────────────────────────────── */
+
+static int __init rcxkm_init(void)
+{
+    int ret = misc_register(&rcxkm_device);
+    if (ret) {
+        pr_err("rcxkm: failed to register misc device (err=%d)\n", ret);
+        return ret;
+    }
+    pr_info("rcxkm: loaded, device /dev/%s\n", DEVICE_NAME);
+    return 0;
+}
+
+static void __exit rcxkm_exit(void)
+{
+    misc_deregister(&rcxkm_device);
+    pr_info("rcxkm: unloaded\n");
+}
+
+module_init(rcxkm_init);
+module_exit(rcxkm_exit);