docs+install: post-rename docs polish, install script, d2 architecture diagram (#26)

* docs: add sanderling bird artwork to README and docs index

* chore: add one-line install script for macOS and Linux

Detects os/arch, resolves latest (or pre-)release, verifies sha256,
and installs the binary into $HOME/.sanderling/bin.

* docs: use the one-line installer in getting-started

Replaces the broken `<version>` placeholder snippets with the
install.sh one-liner.

* docs: drop filler line under the install one-liner

* docs: rename index heading to Sanderling Manual

* docs(style): adopt JetBrains Mono and uppercase brand mark

* docs(getting-started): use justfile flow for folio sample

* docs(writing-specs): drop 'coming soon' notes for eventually and implies

* docs(inspect): rewrite layout for tabbed state panels and metrics chart

* docs(inspect): add UI screenshot

* docs: add Inspect to sidebar and index

* docs: restore mermaid bootstrap script in page template

* docs(style): constrain article images to content width

* docs(inspect): drop layout prose, keep what the screenshot doesn't show

* docs(architecture): add d2 source for architecture diagram

Replaces the in-page mermaid block with a d2-rendered SVG. Generated
outputs (svg/png) stay out of git; only the .d2 source is checked in.

* build(docs): render d2 diagrams into build/site/_assets/diagrams

* docs(architecture): swap mermaid block for rendered d2 svg

* ci(docs): install d2 before building the site

* docs(architecture): tighten layout and reroute label-crossing edges

Flip device/sidecar order so trace writer drops cleanly to runs/
without cutting through the JVM cell, right-align the inspect row
via a pad column, and tune grid gaps to keep gRPC and Unix socket
labels off the SANDERLING boundary.

docs/manual/getting-started.md

@@ -18,22 +18,10 @@ Run `sanderling doctor` to check the host environment.
 
 ### CLI
 
-macOS arm64:
-
 ```sh
-curl -L https://github.com/priyanshujain/sanderling/releases/latest/download/sanderling_<version>_darwin_arm64.tar.gz | tar xz
-./sanderling version
+curl -fsSL https://raw.githubusercontent.com/priyanshujain/sanderling/master/install.sh | bash
 ```
 
-Linux amd64:
-
-```sh
-curl -L https://github.com/priyanshujain/sanderling/releases/latest/download/sanderling_<version>_linux_amd64.tar.gz | tar xz
-./sanderling version
-```
-
-Pre-built for `darwin/arm64`, `darwin/amd64`, `linux/amd64`, `linux/arm64`.
-
 ### Spec package (npm)
 
 ```sh
@@ -50,21 +38,22 @@ dependencies {
 
 ## Your first run
 
-The repo ships a working sample at `examples/folio`. From that directory:
+The repo ships a working sample at `examples/folio`, a Kotlin Multiplatform app with a TypeScript spec under `sanderling/spec.ts`. Install `just`, then from `examples/folio`:
 
 ```sh
-npm install
-(cd android && ./gradlew installDebug)
-sanderling test \
-  --spec spec.ts \
-  --bundle-id app.folio \
-  --platform android \
-  --duration 2m
+just install   # build and install the folio APK on a booted emulator or device
+just test      # run the spec
 ```
 
-Pass `--avd <name>` only when no device is connected and you have multiple AVDs; otherwise sanderling uses the connected device or boots the single AVD it finds.
+With no device connected and multiple AVDs, pick one:
 
-When the run ends, the trace lands in `runs/<timestamp>/`:
+```sh
+AVD=Pixel_7 just test
+```
+
+Persistent settings can live in a `.env` alongside the justfile (`AVD=Pixel_7`, `DURATION=5m`, and so on).
+
+When the run ends, the trace lands in `sanderling/runs/<timestamp>/`:
 
 ```
 runs/2026-04-18T12-34-56/
@@ -73,6 +62,6 @@ runs/2026-04-18T12-34-56/
 └── meta.json
 ```
 
-Open the screenshots directory to scrub visually, or read `trace.jsonl` step by step.
+Browse it with `sanderling inspect` (see [inspect](./inspect.html)), or read `trace.jsonl` step by step.
 
 Next: [writing specs](./writing-specs.html).