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.

10_devices/input.md

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+[← Home](../README.md) · [Devices](README.md)
+
+# input.device — Event Stream Merging
+
+## Overview
+
+`input.device` merges events from keyboard, mouse, gameport, and timer into a single input stream that feeds Intuition. Input handlers can be installed at various priorities to filter, modify, or consume events.
+
+---
+
+## Handler Priority Levels
+
+| Priority | Consumer |
+|---|---|
+| 100 | System reserved |
+| 51+ | Custom high-priority handlers |
+| 50 | Intuition |
+| 20 | Console.device |
+| 0 | Default |
+
+---
+
+## Commands
+
+| Code | Constant | Description |
+|---|---|---|
+| 9 | `IND_ADDHANDLER` | Add input handler |
+| 10 | `IND_REMHANDLER` | Remove input handler |
+| 11 | `IND_WRITEEVENT` | Inject an InputEvent into the stream |
+| 12 | `IND_SETTHRESH` | Set double-click threshold |
+| 13 | `IND_SETPERIOD` | Set key repeat period |
+| 14 | `IND_SETMPORT` | Set mouse port type |
+| 15 | `IND_SETMTRIG` | Set mouse trigger |
+| 16 | `IND_SETMTYPE` | Set mouse type |
+
+---
+
+## References
+
+- NDK39: `devices/input.h`
+- `09_intuition/input_events.md` — handler installation example