diff --git a/.gitattributes b/.gitattributes
new file mode 100644
index 0000000..c4179a4
--- /dev/null
+++ b/.gitattributes
@@ -0,0 +1,6 @@
+# Keep the repo normalized to LF, but check Windows launchers out with CRLF:
+# cmd.exe can misparse LF-only batch files (labels and parenthesized blocks).
+* text=auto
+*.cmd text eol=crlf
+*.ps1 text eol=crlf
+*.png binary
diff --git a/.github/workflows/tests.yml b/.github/workflows/tests.yml
new file mode 100644
index 0000000..b034b5e
--- /dev/null
+++ b/.github/workflows/tests.yml
@@ -0,0 +1,32 @@
+# Runs the test suite on Windows (HogWatch uses Windows-only APIs: ICMP via
+# iphlpapi and ETW) for every pull request and every push to main.
+name: tests
+
+on:
+  push:
+    branches: [main]
+  pull_request:
+
+permissions:
+  contents: read
+
+jobs:
+  test:
+    runs-on: windows-latest
+    timeout-minutes: 10
+    steps:
+      - uses: actions/checkout@v4
+
+      - uses: actions/setup-python@v5
+        with:
+          python-version: "3.13"
+          cache: pip
+
+      - name: Install dependencies
+        run: python -m pip install -r requirements.txt
+
+      - name: Unit and integration tests
+        run: python -m unittest discover -s tests -v
+
+      - name: Dashboard script syntax
+        run: node --check hogwatch/static/app.js
diff --git a/README.md b/README.md
index 658a19c..f8b51dd 100644
--- a/README.md
+++ b/README.md
@@ -1,8 +1,17 @@
 # HogWatch
 
+[![tests](https://github.com/MSabacreationslab/hogwatch/actions/workflows/tests.yml/badge.svg)](https://github.com/MSabacreationslab/hogwatch/actions/workflows/tests.yml)
+
 Finds out **who** is slowing the home internet to a crawl, **when**, and **what
 they're probably doing**, and shows it on a dashboard at <http://127.0.0.1:8765/>.
 
+<picture>
+  <source media="(prefers-color-scheme: dark)" srcset="docs/dashboard-dark.png">
+  <img alt="HogWatch dashboard during a slowdown: a roommate's upload is named as the cause, and short lag spikes are traced to the wireless link between two eeros" src="docs/dashboard-light.png">
+</picture>
+
+<sub>Screenshot uses demo data; device names and rooms are made up.</sub>
+
 It watches three things at once:
 
 | What | How | Needs |
diff --git a/docs/dashboard-dark.png b/docs/dashboard-dark.png
new file mode 100644
index 0000000..8c739eb
Binary files /dev/null and b/docs/dashboard-dark.png differ
diff --git a/docs/dashboard-light.png b/docs/dashboard-light.png
new file mode 100644
index 0000000..68696ae
Binary files /dev/null and b/docs/dashboard-light.png differ
diff --git a/hogwatch/static/app.js b/hogwatch/static/app.js
index 38be047..79eaf5a 100644
--- a/hogwatch/static/app.js
+++ b/hogwatch/static/app.js
@@ -26,7 +26,7 @@ const s = (tag, attrs, ...kids) => build(document.createElementNS(SVGNS, tag), a
 /* ------------------------------------------------------------------ formatting */
 
 const fmtRate = (x) => (x == null ? "–" : x < 0.05 ? "0" : x < 10 ? x.toFixed(1) : Math.round(x).toLocaleString());
-const fmtMs = (x) => (x == null ? "–" : Math.round(x).toLocaleString());
+const fmtMs = (x) => (x == null ? "–" : x < 1 ? "<1" : Math.round(x).toLocaleString());
 function fmtVolume(mb) {
   if (mb == null) return "–";
   if (mb >= 1000) return (mb / 1000).toFixed(mb >= 10000 ? 0 : 1) + " GB";
@@ -56,6 +56,9 @@ const KIND_LABEL = {
 
 const state = { hours: 1, now: null, timeline: null, usage: null, incidents: null, incidentLimit: 15, offline: false };
 try { const saved = +localStorage.getItem("hw-hours"); if (saved) state.hours = saved; } catch (e) { /* storage blocked */ }
+// A link like /?hours=24 opens that range directly (handy for bookmarks).
+const linkedHours = +new URLSearchParams(location.search).get("hours");
+if ([1, 6, 24, 168].includes(linkedHours)) state.hours = linkedHours;
 
 async function getJSON(path) {
   const r = await fetch(path, { cache: "no-store" });