diff --git a/FIXDRY.md b/FIXDRY.md
deleted file mode 100644
index cd9e46e5..00000000
--- a/FIXDRY.md
+++ /dev/null
@@ -1,40 +0,0 @@
-# DRY / low-code replacement audit
-
-This file tracks places where OpenLogi carries general-purpose infrastructure code that can be replaced by mature crates. The goal is not to add dependencies for their own sake, but to delete code where an external crate is a better source of truth.
-
-## Low-risk replacements to do first
-
-- [x] Replace `xtask`'s custom temporary-directory guard with `tempfile`.
-- [x] Replace `xtask`'s custom `PATH` scanning with `which`.
-- [x] Replace macOS LaunchAgent plist string rendering / XML escaping with `plist`.
-- [x] Replace hand-built GUI `file://` URLs with `url::Url::from_file_path`.
-
-## Worth doing next
-
-- [x] Replace `openlogi-assets::http::write_replace` with `atomic-write-file`, preserving atomic replacement and symlink safety.
-- [x] Replace recursive asset-cache directory walking with `walkdir`.
-- [x] Replace `xtask` command orchestration with `xshell`.
-- [x] Replace stale-agent process discovery/signalling through `pgrep`/`kill` with `sysinfo`.
-- [x] Replace `xtask` file/path helpers with `fs-err` and `path-absolutize`.
-- [x] Replace remaining `xtask` production file operations with `fs-err`.
-- [x] Replace `xtask`'s hand-written SHA-256 file loop with `sha2_hasher`.
-- [x] Replace `xtask` manifest tests' custom temp directory with `tempfile`.
-- [x] Replace macOS iconset shell-out (`sips` + `iconutil`) with `image` + `icns`.
-- [x] Replace GUI asset-sync retry delay math with `backon`'s exponential backoff.
-- [x] Replace generic GUI/agent `open` shell-outs with `opener`.
-
-## Needs behavior tests before replacing
-
-- [x] Evaluate `etcetera` for XDG-style config/data/runtime paths. Adopted `etcetera::base_strategy::Xdg`, not platform-native macOS paths.
-- [x] Evaluate `fluent-langneg` for locale matching, while keeping OpenLogi's shipped-locale policy for Chinese, Portuguese, and Norwegian variants.
-
-## Keep custom for now
-
-- `openlogi-core::single_instance`: `single-instance` uses different backends (for example abstract Unix sockets on Linux) and does not preserve OpenLogi's data-dir lock-file path, per-role names, and error classification closely enough to be a safe deletion.
-- Agent tray Quit's `openlogi://quit` dispatch keeps `std::process::Command::output()` intentionally: it blocks until LaunchServices accepts the Apple Event, while generic opener crates only guarantee process spawn.
-- GUI helper launch keeps `/usr/bin/open -g -n` intentionally: it needs LaunchServices-specific flags to start the packaged agent under its own TCC identity, which generic opener crates do not expose.
-- Agent autostart install keeps direct `systemctl` calls because it is managing systemd user units, not merely opening or spawning an arbitrary program.
-- Self-restart and `disclaim` launches stay custom because they are process identity / update lifecycle boundaries, not generic command orchestration.
-- `openlogi-hook`: event suppression/rewriting and foreground-app lookup are OpenLogi-specific and not covered cleanly by generic input crates.
-- `openlogi-inject`: platform-specific action synthesis may overlap with `enigo`, but current semantics are narrower and more controlled.
-- `openlogi-hid` / vendored `openlogi-hidpp`: the right path is upstreaming OpenLogi-specific fixes, not replacing the fork blindly.
diff --git a/devenv.lock b/devenv.lock
index 9fc0737c..8bf78b3a 100644
--- a/devenv.lock
+++ b/devenv.lock
@@ -67,11 +67,11 @@
         ]
       },
       "locked": {
-        "lastModified": 1779592685,
-        "narHash": "sha256-p9d56GezhHRf4QfANxwa1d+fvwShvjB5XUhdIl7WEd0=",
+        "lastModified": 1783144302,
+        "narHash": "sha256-NQnzmXwpEAd5tjMBh2+P/y9NknF+WHv5+6yoXoN4h/Y=",
         "owner": "oxalica",
         "repo": "rust-overlay",
-        "rev": "3a58b199e7c83a80b85c28044f808085ba7e941c",
+        "rev": "fe5aee0952e8e1525533d61defd9e36513db811b",
         "type": "github"
       },
       "original": {
diff --git a/docs/DECISIONS.md b/docs/DECISIONS.md
new file mode 100644
index 00000000..d060866a
--- /dev/null
+++ b/docs/DECISIONS.md
@@ -0,0 +1,34 @@
+# Decision log
+
+Durable "why we did it this way" records that are not obvious from the code.
+Add a dated entry when a non-obvious architectural or dependency decision is
+made or revisited.
+
+## 2026-07: Infrastructure we keep custom instead of using a crate
+
+A dependency audit replaced most general-purpose infrastructure code with
+mature crates (`tempfile`, `which`, `plist`, `walkdir`, `xshell`, `sysinfo`,
+`fs-err`, `backon`, `opener`, `etcetera`, and others — see the git history of
+`FIXDRY.md` for the full list). The following stayed custom, deliberately:
+
+- `openlogi-core::single_instance`: the `single-instance` crate uses different
+  backends (for example abstract Unix sockets on Linux) and does not preserve
+  OpenLogi's data-dir lock-file path, per-role names, and error classification
+  closely enough to be a safe deletion.
+- Agent tray Quit's `openlogi://quit` dispatch keeps
+  `std::process::Command::output()` intentionally: it blocks until
+  LaunchServices accepts the Apple Event, while generic opener crates only
+  guarantee process spawn.
+- GUI helper launch keeps `/usr/bin/open -g -n` intentionally: it needs
+  LaunchServices-specific flags to start the packaged agent under its own TCC
+  identity, which generic opener crates do not expose.
+- Agent autostart install keeps direct `systemctl` calls because it is managing
+  systemd user units, not merely opening or spawning an arbitrary program.
+- Self-restart and `disclaim` launches stay custom because they are process
+  identity / update lifecycle boundaries, not generic command orchestration.
+- `openlogi-hook`: event suppression/rewriting and foreground-app lookup are
+  OpenLogi-specific and not covered cleanly by generic input crates.
+- `openlogi-inject`: platform-specific action synthesis may overlap with
+  `enigo`, but current semantics are narrower and more controlled.
+- `openlogi-hid` / vendored `openlogi-hidpp`: the right path is upstreaming
+  OpenLogi-specific fixes, not replacing the fork blindly.