fix(starlark): restore the remaining eleven routes, so the app store works

The Pixlet button was the reported symptom; the app store is dead the
same way. #330 dropped all thirteen Starlark routes, and browse,
categories and install are what the store page is built on -- each
answering the generic 404, which from the UI is indistinguishable from
an empty store.

Restores the other eleven from 1c4d5c52^: apps list and detail, delete,
per-app config get/put, toggle, render, manual .star upload, and the
Tronbyte repository browse/categories/install. Their dependency closure
came with them (8 helpers, resolved by walking the handlers' references
rather than by eye), plus the Tuple and Type imports the old file had.

Two changes rather than a straight revert. The restored handlers used
`request.get_json()` where the file has since standardised on
`silent=True`: without it Werkzeug raises on a bodyless POST before the
handler's own `if not data` guard runs, so the caller gets a framework
error instead of the declared 400. test_api_v3_optional_body.py already
checks for exactly that and caught all three.

test_every_endpoint_the_frontend_calls_is_registered reads the URLs out
of plugins_manager.js and matches each through the URL map, so a rewrite
of this file cannot quietly drop the set again -- one assertion over the
frontend's own list is what would have caught #330.

26 tests, 17 of which fail against main. Full core suite: 3973 passed.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_014RRtqXDCnvnY6EQwhT5CV9

test/web_interface/test_starlark_pixlet_routes.py

@@ -0,0 +1,201 @@
+"""The Starlark routes the frontend calls must exist.
+
+`plugins_manager.js` posts to /api/v3/starlark/install-pixlet and then reloads
+/api/v3/starlark/status. Neither route existed: #330 rewrote api_v3.py and
+dropped all thirteen Starlark routes that #253 had added, so both calls fell
+through to Flask's 404 handler, which answers
+
+    {"status": "error", "message": "Resource not found"}
+
+and the button reported "Pixlet install failed: Resource not found" -- a
+message that names neither the resource nor the cause.
+
+These assert the routes are registered and answer in the shape the frontend
+reads, so a future rewrite of this file cannot silently drop them again.
+"""
+
+import json
+from unittest.mock import MagicMock, patch
+
+import pytest
+
+
+@pytest.fixture
+def client():
+    from web_interface.app import app
+    app.config['TESTING'] = True
+    with app.test_client() as c:
+        yield c
+
+
+class TestRoutesAreRegistered:
+    """The failure was a missing route, so check the URL map directly.
+
+    All thirteen, not just the two the Pixlet button needs: #330 dropped the
+    lot, and the app store page is built on repository/browse,
+    repository/categories and repository/install, which 404 the same way.
+    """
+
+    @pytest.mark.parametrize("rule,method", [
+        ("/api/v3/starlark/install-pixlet", "POST"),
+        ("/api/v3/starlark/status", "GET"),
+        ("/api/v3/starlark/apps", "GET"),
+        ("/api/v3/starlark/upload", "POST"),
+        ("/api/v3/starlark/repository/browse", "GET"),
+        ("/api/v3/starlark/repository/categories", "GET"),
+        ("/api/v3/starlark/repository/install", "POST"),
+        ("/api/v3/starlark/apps/<app_id>", "GET"),
+        ("/api/v3/starlark/apps/<app_id>", "DELETE"),
+        ("/api/v3/starlark/apps/<app_id>/config", "GET"),
+        ("/api/v3/starlark/apps/<app_id>/config", "PUT"),
+        ("/api/v3/starlark/apps/<app_id>/toggle", "POST"),
+        ("/api/v3/starlark/apps/<app_id>/render", "POST"),
+    ])
+    def test_route_exists(self, rule, method):
+        from web_interface.app import app
+        matches = [r for r in app.url_map.iter_rules()
+                   if r.rule == rule and method in r.methods]
+        assert matches, (
+            f"{method} {rule} is not registered; the frontend calls it and "
+            "would get Flask's generic 'Resource not found'")
+
+
+class TestInstallPixlet:
+    def test_it_does_not_404(self, client):
+        with patch('web_interface.blueprints.api_v3.subprocess.run') as run:
+            run.return_value = MagicMock(returncode=0, stdout="ok", stderr="")
+            resp = client.post('/api/v3/starlark/install-pixlet')
+        assert resp.status_code != 404, "the route is still missing"
+        assert resp.get_json().get('message') != 'Resource not found'
+
+    def test_success_is_reported_in_the_shape_the_button_reads(self, client):
+        with patch('web_interface.blueprints.api_v3.subprocess.run') as run:
+            run.return_value = MagicMock(returncode=0, stdout="done", stderr="")
+            resp = client.post('/api/v3/starlark/install-pixlet')
+        body = resp.get_json()
+        assert body['status'] == 'success', body
+        assert 'message' in body, "the JS shows data.message on success"
+
+    def test_a_failed_download_says_why(self, client):
+        with patch('web_interface.blueprints.api_v3.subprocess.run') as run:
+            run.return_value = MagicMock(returncode=1, stdout="", stderr="no such release")
+            resp = client.post('/api/v3/starlark/install-pixlet')
+        body = resp.get_json()
+        assert body['status'] == 'error'
+        assert 'no such release' in body['message'], \
+            "the installer's own stderr is what tells the user what went wrong"
+
+    def test_a_timeout_is_reported_rather_than_hanging(self, client):
+        import subprocess as sp
+        with patch('web_interface.blueprints.api_v3.subprocess.run',
+                   side_effect=sp.TimeoutExpired(cmd='x', timeout=300)):
+            resp = client.post('/api/v3/starlark/install-pixlet')
+        assert resp.get_json()['status'] == 'error'
+        assert 'timed out' in resp.get_json()['message'].lower()
+
+
+class TestStarlarkStatus:
+    def test_it_does_not_404(self, client):
+        resp = client.get('/api/v3/starlark/status')
+        assert resp.status_code != 404, "the route is still missing"
+        assert resp.get_json().get('message') != 'Resource not found'
+
+    def test_it_reports_pixlet_availability_without_the_plugin_loaded(self, client):
+        # The status call runs before install too -- it must answer even when
+        # starlark-apps is not loaded, which is the state a user is in when
+        # they press the install button for the first time.
+        with patch('web_interface.blueprints.api_v3._get_starlark_plugin', return_value=None):
+            resp = client.get('/api/v3/starlark/status')
+        body = resp.get_json()
+        assert body['status'] == 'success', body
+        assert 'pixlet_available' in body
+        assert body['plugin_loaded'] is False
+
+
+class TestTheInstallerScriptIsActuallyThere:
+    def test_download_pixlet_script_exists_and_is_executable(self):
+        # install_pixlet chmods and runs this; a missing file is the one error
+        # it reports as a 404 of its own, which would look identical to the
+        # bug being fixed here.
+        import os
+        from pathlib import Path
+        from web_interface.blueprints.api_v3 import PROJECT_ROOT
+        script = Path(PROJECT_ROOT) / 'scripts' / 'download_pixlet.sh'
+        assert script.is_file(), f"{script} is missing; install_pixlet would 404"
+        assert os.access(script, os.R_OK)
+
+
+class TestTheAppStoreFlow:
+    """Browsing and installing from the Tronbyte repository.
+
+    These are the calls the app store page makes. Each returned the generic
+    "Resource not found" before this change, which is indistinguishable from
+    an empty store.
+    """
+
+    def test_browse_does_not_404(self, client):
+        resp = client.get('/api/v3/starlark/repository/browse')
+        assert resp.status_code != 404, "the store cannot list anything"
+        assert resp.get_json().get('message') != 'Resource not found'
+
+    def test_categories_does_not_404(self, client):
+        resp = client.get('/api/v3/starlark/repository/categories')
+        assert resp.status_code != 404
+        assert resp.get_json().get('message') != 'Resource not found'
+
+    def test_installed_apps_list_does_not_404(self, client):
+        resp = client.get('/api/v3/starlark/apps')
+        assert resp.status_code != 404
+        assert resp.get_json().get('message') != 'Resource not found'
+
+    def test_repository_install_rejects_a_missing_body_rather_than_404ing(self, client):
+        # A 400/422 here is the route working: it received the call and said
+        # what was wrong. A 404 means it was never reached at all.
+        resp = client.post('/api/v3/starlark/repository/install',
+                           json={}, content_type='application/json')
+        assert resp.status_code != 404, "the install route is still missing"
+        assert resp.get_json().get('message') != 'Resource not found'
+
+    def test_upload_rejects_an_empty_post_rather_than_404ing(self, client):
+        resp = client.post('/api/v3/starlark/upload')
+        assert resp.status_code != 404
+        assert resp.get_json().get('message') != 'Resource not found'
+
+
+class TestNoStarlarkRouteIsMissing:
+    """A single check that the whole set is present.
+
+    #330 removed all thirteen at once by rewriting this file. One assertion
+    over the frontend's own list is what would have caught that.
+    """
+
+    def test_every_endpoint_the_frontend_calls_is_registered(self):
+        import re
+        from pathlib import Path
+        from werkzeug.exceptions import MethodNotAllowed, NotFound
+        from web_interface.app import app
+
+        root = Path(__file__).resolve().parent.parent.parent
+        js = (root / 'web_interface' / 'static' / 'v3' / 'plugins_manager.js').read_text()
+
+        # The frontend builds some of these with template literals, e.g.
+        # `/api/v3/starlark/apps/${appId}/toggle`. Substitute a placeholder so
+        # the URL is concrete, then let Werkzeug match it the way a request
+        # would -- string comparison cannot see <app_id> rules.
+        raw = set(re.findall(r"[\'\"`](/api/v3/starlark/[^\'\"`\s]*)", js))
+        urls = set()
+        for u in raw:
+            u = re.sub(r"\$\{[^}]*\}", "probe", u)
+            urls.add(u.rstrip('/') or u)
+        assert urls, "found no starlark calls in the frontend -- did the file move?"
+
+        adapter = app.url_map.bind('localhost')
+        missing = []
+        for u in sorted(urls):
+            try:
+                adapter.match(u, method='GET')
+            except MethodNotAllowed:
+                pass          # route exists, just not for GET -- fine
+            except NotFound:
+                missing.append(u)
+        assert not missing, f"the frontend calls these and they are not registered: {missing}"