fix: v1.1.1 — deb conflict with input-sync + Illegal instruction (closes #1)

- Cargo.toml: add Conflicts/Replaces: input-sync to deb metadata so dpkg
  automatically removes the old Tauri-based package on upgrade; fixes
  "trying to overwrite .../inputsync.png which is also in package input-sync"
- Cargo.toml: bump version to 1.1.1
- CHANGELOG.md: document both fixes (deb conflict + AVX2 crash)

Fixes: #1

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: KaiCreates

CHANGELOG.md

@@ -7,6 +7,27 @@ Versions follow [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
 ---
 
+## [1.1.1] — 2026-03-08
+
+### Fixed
+
+**Linux — .deb install fails with file conflict against old `input-sync` package:**
+- Installing `inputsync_1.1.1_amd64.deb` on a machine that previously had the old
+  Tauri-based `input-sync` package would fail: dpkg refused to overwrite shared icon
+  files (`/usr/share/icons/hicolor/*/apps/inputsync.png`) owned by `input-sync`.
+- Added `Conflicts: input-sync` and `Replaces: input-sync` to the package metadata.
+  dpkg now automatically removes the old package when installing InputSync 1.1.1+.
+- The "Broken pipe / lzma write error" was a side-effect of dpkg aborting mid-extract
+  on the conflict — resolved by the same fix.
+
+**Linux — "Illegal instruction (core dumped)" on non-AVX2 CPUs:**
+- Binary was compiled with `target-cpu=native` (AVX2/AVX512 instructions) and cached
+  dependency objects were reused even after changing the CPU target. Full `cargo clean`
+  plus `-C target-feature=-avx,-avx2,-avx512f` ensures the binary runs on any x86_64
+  CPU, not just Haswell-era and newer.
+
+---
+
 ## [1.1.0] — 2026-03-08
 
 ### Changed

src-tauri/Cargo.lock

@@ -1,6 +1,6 @@
 [package]
 name = "inputsync"
-version = "1.1.0"
+version = "1.1.1"
 description = "InputSync - Software KVM Switch"
 authors = ["KaiCreates"]
 edition = "2021"
@@ -80,6 +80,8 @@ copyright = "2026 KaiCreates"
 license-file = ["../LICENSE", "0"]
 extended-description = "InputSync is a lightweight, encrypted software KVM switch. Control multiple computers with one keyboard and mouse — no hardware required. Built with pure Rust + egui, no WebView2 or browser engine needed."
 depends = "libgtk-3-0, libx11-6, libxtst6, libxdo3"
+conflicts = ["input-sync"]
+replaces = ["input-sync"]
 section = "utils"
 priority = "optional"
 assets = [