feature: boot.mgr replace hardcoded init sequence with dependency-driven boot manager

Introduce boot.mgr - a self-registering, dependency-ordered boot
initialization framework with barrier-based phasing and glob pattern
matching. Units now declare their own init procedures and dependencies
via registerBoot()/registerBarrier() in their initialization sections,
boot.mgr.run() topologically sorts and executes them.

- Add src/boot/boot.mgr.pas with topoSort, glob matching, barrier
  two-pass algorithm, and boot tree printer
- Gut src/asuro.pas (kmain): now just stores multiboot info, calls
  System.init(), boot.mgr.run, and yield()
- Add initialization sections with registerBoot() to 53 existing units
- Add new units: core.pas, test.pas, driver.storage.boot.pas,
  app.wasm.pas, app.bsod.pas (factored out of asuro.pas)
- Define 9 barrier phases: immediate -> early -> middle -> storage ->
  bus -> device -> bus.late -> late -> final
- Fix xHCI ISR: exclude PRC/WRC from PORTSC change bit clearing to
  prevent race with port reset busy-wait
- Fix driver.bus.usb.core fire_completion_hooks: guard against uint32
  underflow when CompletionHookCount = 0
- Move auto_mount_volumes from device barrier to late barrier so it
  runs after PCI scan discovers storage controllers
- Add toolchain/compile_initcalls.sh for boot entry extraction
- Add Boot Registration sections to all 51 doc files; create 4 new
  doc files; rewrite boot.mgr.md; update mkdocs.yml nav

src/core/core.panic.pas

@@ -76,6 +76,7 @@ procedure registerHaltProc(proc : THaltProc);
 implementation
 
 uses    
+    boot.mgr,
     io.syslog,
     debug.tracer,
     driver.video,
@@ -866,6 +867,8 @@ var
     traceCard     : Plv_obj;
     traceHeader   : Plv_obj;
 begin
+    io.syslog.logln('PANIC', 'Initializing Core Panic Handler.');
+
     { Allocate text buffers — kernel-heap, persist for system lifetime }
     faultTextBuf := pchar(kalloc(512));
     regTextBuf := pchar(kalloc(PANIC_TEXT_BUF_SIZE));
@@ -1100,24 +1103,11 @@ begin
 
     { Mark BSOD screen as ready for panic rendering }
     ScreenReady := true;
+
+    io.syslog.logln('PANIC', 'Core Panic Handler Initialized.');
 end;
 
-{ ====================================================================
-  Unit initialization — set safe defaults before init() is called.
-  ==================================================================== }
-begin
-    ScreenReady := false;
-    PanicInProgress := false;
-    HaltProc := @fallbackHalt;
-    faultTextBuf := nil;
-    regTextBuf := nil;
-    traceTextBuf := nil;
-    systemTextBuf := nil;
-    bsodScreen := nil;
-    faultLabel := nil;
-    regLabel := nil;
-    traceLabel := nil;
-    systemLabel := nil;
-    panicTexture := nil;
-    panicDsc := nil;
-end.
+initialization
+    boot.mgr.registerBoot('core.panic', @init, 'Core Panic Handler', 'arch.*.panic');
+
+end.

src/core/core.pas

@@ -0,0 +1,20 @@
+unit core;
+
+interface
+
+uses
+    boot.mgr,
+    core.rand,
+    driver.timer.rtc;
+
+implementation
+
+procedure init();
+begin
+    core.rand.srand((getDateTime.Seconds SHL 24) OR (getDateTime.Minutes SHL 16) OR (getDateTime.Hours SHL 8) OR (getDateTime.Day));
+end;
+
+initialization
+    boot.mgr.registerBoot('core', @init, 'Core Initialization', BOOT_MGR_BARRIER_LATE);
+
+end.