docs(amiga): complete AmigaOS 3.1/3.2 developer reference — 172 files across 17 sections

Comprehensive technical documentation covering:
- Hardware: OCS/ECS/AGA custom chip registers, Copper & Blitter deep dives
- Boot sequence: cold boot through startup-sequence
- Binary format: HUNK executable spec, relocation, debug info
- Linking & ABI: .fd files, LVO tables, register calling conventions
- Exec kernel: tasks, interrupts, memory, signals, semaphores
- AmigaDOS: file I/O, FFS/OFS layout, CLI/Shell scripting
- Graphics: planar bitmaps, Copper programming, HAM/EHB modes
- Intuition: screens, windows, IDCMP, BOOPSI
- Devices: trackdisk, SCSI, serial, timer, audio, keyboard
- Libraries: utility, expansion, IFFParse, locale, ARexx
- Networking: bsdsocket API, SANA-II, TCP/IP stack comparison
- Toolchain: GCC, vasm/vlink, SAS/C, NDK, debugging
- Reverse engineering: IDA/Ghidra setup, compiler fingerprints, case studies
- CPU & MMU: 68040/060 emulation libs, PMMU, cache management
- Driver development: SANA-II, Picasso96/RTG, AHI audio

All files include breadcrumb navigation. No local paths or proprietary content.

11_libraries/icon.md

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+[← Home](../README.md) · [Libraries](README.md)
+
+# icon.library — Workbench Icons (.info Files)
+
+## Overview
+
+Every Workbench-visible file has a companion `.info` file containing its icon imagery, tooltypes, and default tool. `icon.library` provides reading/writing these structures.
+
+---
+
+## struct DiskObject
+
+```c
+/* workbench/workbench.h — NDK39 */
+struct DiskObject {
+    UWORD           do_Magic;      /* $E310 = WB_DISKMAGIC */
+    UWORD           do_Version;    /* WB_DISKVERSION */
+    struct Gadget   do_Gadget;     /* the icon gadget */
+    UBYTE           do_Type;       /* WBDISK, WBTOOL, WBPROJECT, etc. */
+    char           *do_DefaultTool; /* default tool path */
+    char          **do_ToolTypes;   /* NULL-terminated string array */
+    LONG            do_CurrentX;   /* icon X position */
+    LONG            do_CurrentY;   /* icon Y position */
+    BPTR            do_DrawerData;  /* drawer window position (BPTR) */
+    char           *do_ToolWindow;  /* tool window spec */
+    LONG            do_StackSize;   /* stack size for tool */
+};
+```
+
+---
+
+## Icon Types
+
+| Constant | Value | Description |
+|---|---|---|
+| `WBDISK` | 1 | Disk/volume icon |
+| `WBDRAWER` | 2 | Drawer (directory) |
+| `WBTOOL` | 3 | Executable tool |
+| `WBPROJECT` | 4 | Project (document) |
+| `WBGARBAGE` | 5 | Trashcan |
+| `WBDEVICE` | 6 | Device |
+| `WBKICK` | 7 | Kickstart disk |
+| `WBAPPICON` | 8 | AppIcon (OS 2.0+) |
+
+---
+
+## ToolTypes
+
+ToolTypes are key=value strings stored in `do_ToolTypes`:
+
+```c
+struct DiskObject *dobj = GetDiskObject("myapp");
+if (dobj) {
+    char *val = FindToolType(dobj->do_ToolTypes, "PUBSCREEN");
+    if (val) Printf("Screen: %s\n", val);
+    if (MatchToolValue(FindToolType(dobj->do_ToolTypes, "FLAGS"), "DEBUG"))
+        Printf("Debug mode\n");
+    FreeDiskObject(dobj);
+}
+```
+
+---
+
+## References
+
+- NDK39: `workbench/workbench.h`, `workbench/icon.h`