Drop the extension, and give the test suite a front door

Phase 6, the last of the fresh-install spec.

159 scripts lose their .sh: 110 contracts, 47 Vicinae commands, 2 compositor
contracts. A shebang and the executable bit already select the interpreter. The
extension only ever added something that had to stay in sync, and the rename
proved the point twice over in the space of an hour.

The spec's stated risk was Vicinae's script discovery. One script was renamed and
reloaded on its own before the other 46 followed; it came back as
scripts:panama.capture and all 47 resolve. What the probe turned up instead is
that the extension was never only a filename: Vicinae's command IDs embed it, so
every ID changed. Nothing in this repository refers to them, so nothing breaks.
The only trace is Vicinae's metadata.json, whose visited map had two Panama
entries that are now orphaned -- two commands lost their usage ranking and will
earn it back. Worth knowing before anyone renames these again on a machine that
has a keybind pointing at one.

Rewriting the references by exact filename missed two things it structurally
could not see: a name built from a variable, settings-$page.sh, and a glob,
-name '*.sh'. Both were in the contract that counts the generated commands, which
promptly reported 47 expected and 0 found. The mechanical part of a rename is the
part that looks finished.

The three subcommands. panama doctor fronts a health check that already existed
and already ran at the end of every install but could not be reached from a
terminal. panama upgrade re-runs the installer from anywhere. panama test runs
the suite, which had no entry point at all -- 121 files that were the main safety
net in this repository and were invisible in it.

Writing that runner found three tests nothing was running.
calendar_agenda_bridge_test, home_assistant_bridge_test and kdeconnect_bridge_test
are unittest suites without the executable bit, so no contract invoked them and
the first draft of the runner skipped them silently. All three pass, and have
passed unobserved for weeks. The runner collects *_test.py as well now, because a
runner with a blind spot is worse than no runner for the same reason a dependency
checker with one is: it reports PASS.

Six worktrees pruned. Each was re-checked rather than trusted to the spec's list,
and two needed it: panama-commands is not on feat/panama-commands but on
feat/gnome-tweaks-parity, and fix/panama-displays-review reads [ahead 3] -- ahead
of its remote, not of main, with every commit patch-equivalent to landed work.
roadmap-completion stays; it has five commits that are genuinely unlanded. The
branches are left alone: pruning a worktree costs nothing, deleting a branch is a
decision.

121 contracts pass.

Claude-Session: https://claude.ai/code/session_01NvgBuSWB5sE43yWmg21ozj

tests/quickshell/display-arrangement-contract

@@ -0,0 +1,111 @@
+#!/usr/bin/env bash
+
+set -euo pipefail
+
+repo_dir="$(cd "$(dirname "${BASH_SOURCE[0]}")/../.." && pwd)"
+component="$repo_dir/config/dot/quickshell/modules/settings/DisplayArrangement.qml"
+page="$repo_dir/config/dot/quickshell/modules/settings/DisplaysPage.qml"
+harness="$repo_dir/config/dot/quickshell/display-arrangement-harness.qml"
+identify="$repo_dir/config/dot/quickshell/modules/settings/DisplayIdentify.qml"
+service="$repo_dir/config/dot/quickshell/services/Displays.qml"
+shell="$repo_dir/config/dot/quickshell/shell.qml"
+
+fail() {
+    printf 'display arrangement contract: %s\n' "$1" >&2
+    exit 1
+}
+
+[[ -f "$component" ]] || fail 'DisplayArrangement.qml is missing'
+for contract in \
+    'required property var displayService' \
+    'property var draftLayout:' \
+    'function setDraftPosition(' \
+    'function nudge(' \
+    'function applyDraft(' \
+    'function makePrimary(' \
+    'Accessible.name: "Move "' \
+    'DragHandler {' \
+    'Keys.onPressed:'; do
+    rg -Fq "$contract" "$component" \
+        || fail "arrangement interaction is missing: $contract"
+done
+rg -Fq 'DisplayArrangement {' "$page" \
+    || fail 'Displays page does not expose the arrangement canvas'
+rg -Fq 'visible: Displays.monitors.length > 1' "$page" \
+    || fail 'arrangement is shown for a single display'
+[[ -f "$identify" ]] || fail 'DisplayIdentify.qml is missing'
+for contract in \
+    'model: Quickshell.screens' \
+    'WlrLayershell.keyboardFocus: WlrKeyboardFocus.None' \
+    'mask: Region {}' \
+    'visible: Displays.identifying' \
+    'text: String(win.number)' \
+    'text: win.connector'; do
+    rg -Fq "$contract" "$identify" \
+        || fail "display identification overlay is incomplete: $contract"
+done
+rg -Fq 'DisplayIdentify {}' "$shell" \
+    || fail 'display identification overlays are not shell-owned'
+rg -Fq 'function identify()' "$service" \
+    && rg -Fq 'interval: 3000' "$service" \
+    || fail 'display identification does not use one three-second service timer'
+
+state_home="$(mktemp -d /tmp/panama-display-arrangement-state.XXXXXX)"
+harness_pid=""
+cleanup() {
+    [[ "$harness_pid" =~ ^[0-9]+$ ]] && kill "$harness_pid" 2>/dev/null || true
+    rm -rf "$state_home"
+}
+trap cleanup EXIT
+
+XDG_STATE_HOME="$state_home" qs -p "$harness" --daemonize >/dev/null
+for _ in $(seq 1 60); do
+    harness_pid="$(qs list --all 2>/dev/null | awk -v expected="$harness" '
+        /^Instance / {pid=""} /^[[:space:]]*Process ID:/ {pid=$3}
+        /^[[:space:]]*Config path:/ {path=$0; sub(/^[[:space:]]*Config path: /,"",path); if(path==expected) print pid}' | head -1)"
+    [[ "$harness_pid" =~ ^[0-9]+$ ]] \
+        && XDG_STATE_HOME="$state_home" qs -p "$harness" ipc --pid "$harness_pid" show 2>/dev/null \
+            | rg -q '^target display-arrangement-test$' && break
+    sleep 0.1
+done
+[[ "$harness_pid" =~ ^[0-9]+$ ]] || fail 'arrangement harness did not start'
+
+ipc() {
+    XDG_STATE_HOME="$state_home" qs -p "$harness" ipc --pid "$harness_pid" \
+        call display-arrangement-test "$@"
+}
+
+wide="$(ipc status 800)"
+narrow="$(ipc status 500)"
+for snapshot in "$wide" "$narrow"; do
+    jq -e '(.rects | length) == 2
+        and .scale > 0
+        and (.rects[0].width / .rects[0].height - 1.5 | fabs) < 0.0001
+        and (.rects[1].width / .rects[1].height - (2560 / 1440) | fabs) < 0.0001' \
+        <<<"$snapshot" >/dev/null \
+        || fail "canvas lost monitor geometry at a supported width: $snapshot"
+done
+
+drag="$(ipc dragFixture)"
+jq -e '.[0].x == 0 and .[1].x == 3000' <<<"$drag" >/dev/null \
+    || fail "drag release did not snap and apply the complete layout: $drag"
+
+keyboard="$(ipc keyboardFixture)"
+jq -e '.afterArrow == 2990 and .afterShiftArrow == 2890' <<<"$keyboard" >/dev/null \
+    || fail "keyboard movement did not use 10/100 logical-pixel steps: $keyboard"
+
+primary="$(ipc primaryFixture)"
+jq -e '. == [
+    {"name":"DP-2","x":-3000,"y":0,"primary":false},
+    {"name":"HDMI-A-1","x":0,"y":0,"primary":true}
+]' <<<"$primary" >/dev/null \
+    || fail "Make primary did not normalize the selected output to 0,0: $primary"
+
+ipc identify >/dev/null
+[[ "$(ipc identifying)" == "true" ]] \
+    || fail 'identify did not reveal the overlays'
+sleep 3.2
+[[ "$(ipc identifying)" == "false" ]] \
+    || fail 'identify overlays did not disappear after one three-second timer'
+
+printf 'display arrangement contract: PASS\n'