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/io/io.stdio.pas

@@ -15,6 +15,7 @@ unit io.stdio;
 interface
 
 uses
+    boot.mgr,
     memory.heap, core.strings, core.util, arch.x86.util, debug.tracer;
 
 type
@@ -670,4 +671,7 @@ begin
     io.syslog.logln('STDIO', 'Initialized.');
 end;
 
+initialization
+    boot.mgr.registerBoot('io.stdio', @init, 'Standard I/O Abstraction', BOOT_MGR_BARRIER_EARLY);
+
 end.

src/io/io.syslog.pas

@@ -11,6 +11,9 @@ unit io.syslog;
 
 interface
 
+uses
+    boot.mgr;
+
 type
     TLogHook = procedure(msg: pchar);
 
@@ -52,10 +55,11 @@ const
     LINE_BUF_SIZE = 256;
 
 var
-    Hooks     : array[0..MAX_HOOKS-1] of TLogHook;
-    HookCount : uint32 = 0;
-    LineBuf   : array[0..LINE_BUF_SIZE-1] of char;
-    LinePos   : uint32 = 0;
+    Hooks       : array[0..MAX_HOOKS-1] of TLogHook;
+    HookCount   : uint32 = 0;
+    LineBuf     : array[0..LINE_BUF_SIZE-1] of char;
+    LinePos     : uint32 = 0;
+    Initialized : boolean = false;
 
 { ---- Hook management ---- }
 
@@ -110,6 +114,7 @@ end;
 procedure logChar(c: char);
 begin
     { Also send each char to driver.io.serial directly for immediate byte-level output }
+    if not Initialized then exit;  { Avoid calling driver.io.serial before it's ready }
     driver.io.serial.send(COM1, uint8(c), 10000);
     if c = #10 then begin
         dispatchLine;
@@ -285,10 +290,14 @@ begin
         Hooks[i] := nil;
     HookCount := 0;
     LinePos := 0;
+    Initialized:= true;
     { Note: We don't register serialHook here because logChar already sends
       each character to driver.io.serial directly. The hook system is for line-level
       consumers (file logging, debug panels, etc.) that want complete lines.
       If we registered serialHook, driver.io.serial would get double output. }
 end;
 
+initialization
+    boot.mgr.registerBoot('io.syslog', @init, 'Syslog Interface', 'driver.io.serial');
+
 end.