fix(pj_plugins): read manifest encoding as an array of strings

pj_plugins/docs/message-parser-guide.md

@@ -23,7 +23,7 @@ the host, which routes them to the appropriate parser based on encoding name.
 1. Subclass `PJ::MessageParserPluginBase`
 2. Override `parse()` (required) and optionally `bindSchema()`, `saveConfig()`,
    `loadConfig()`
-3. Export with `PJ_MESSAGE_PARSER_PLUGIN(YourClass, R"({"id":"...","name":"...","version":"...","encoding":"..."})")`
+3. Export with `PJ_MESSAGE_PARSER_PLUGIN(YourClass, R"({"id":"...","name":"...","version":"...","encoding":["..."]})")`
 4. Build as a shared library linking `pj_base`
 
 A complete example lives at `pj_plugins/examples/mock_json_parser.cpp`.
@@ -79,7 +79,7 @@ manifest string literal (see Manifest Schema below):
 
 ```cpp
 PJ_MESSAGE_PARSER_PLUGIN(MyJsonParser,
-    R"({"id":"json-parser","name":"JSON Parser","version":"1.0.0","encoding":"json"})")
+    R"({"id":"json-parser","name":"JSON Parser","version":"1.0.0","encoding":["json"]})")
 ```
 
 This generates the `extern "C"` entry point that the host resolves via dlsym.
@@ -326,15 +326,15 @@ it without instantiating the plugin.
 | `id` | string | yes | Stable plugin identifier — used by the host catalog and the marketplace. Must be unique per plugin. |
 | `name` | string | yes | Human-readable plugin name. |
 | `version` | string | yes | Semver version string. |
-| `encoding` | string | yes | Encoding this parser handles, e.g. `"json"`, `"protobuf"`, `"ros1msg"`. The host uses this to match binding requests to parsers. |
+| `encoding` | array of strings | yes | Encodings this parser handles, e.g. `["json"]`, `["protobuf"]`, `["ros1msg", "ros2msg", "cdr"]`. The host uses this list to match binding requests to parsers; one parser may register more than one encoding. |
 
 Example:
 ```json
 {
   "id": "protobuf-parser",
   "name": "Protobuf Parser",
   "version": "1.0.0",
-  "encoding": "protobuf"
+  "encoding": ["protobuf"]
 }
 ```
 

pj_plugins/examples/mock_json_parser.cpp

@@ -23,4 +23,5 @@ class MockJsonParser : public PJ::MessageParserPluginBase {
 }  // namespace
 
 PJ_MESSAGE_PARSER_PLUGIN(
-    MockJsonParser, R"({"id":"mock-json-parser","name":"Mock JSON Parser","version":"1.0.0","encoding":"json"})")
+    MockJsonParser,
+    R"({"id":"mock-json-parser","name":"Mock JSON Parser","version":"1.0.0","encoding":["json"]})")

pj_plugins/examples/mock_schema_parser.cpp

@@ -111,4 +111,4 @@ class MockSchemaParser : public PJ::MessageParserPluginBase {
 
 PJ_MESSAGE_PARSER_PLUGIN(
     MockSchemaParser,
-    R"({"id":"mock-schema-parser","name":"Mock Schema Parser","version":"1.0.0","encoding":"csv_pair"})")
+    R"({"id":"mock-schema-parser","name":"Mock Schema Parser","version":"1.0.0","encoding":["csv_pair"]})")

pj_plugins/include/pj_plugins/host/plugin_catalog.hpp

@@ -42,7 +42,7 @@ struct PluginDescriptor {
   std::string version;
   std::string description;
   std::string category;
-  std::string encoding;                      ///< for message parsers
+  std::vector<std::string> encoding;         ///< for message parsers (one or more)
   std::vector<std::string> file_extensions;  ///< for data sources
   std::vector<std::string> capabilities;     ///< optional capability tags
 };

pj_plugins/src/plugin_catalog.cpp

@@ -246,19 +246,14 @@ Expected<PluginDescriptor> decodeManifest(
   d.file_extensions = *file_extensions;
   d.capabilities = *capabilities;
 
-  if (family == PluginFamily::kMessageParser) {
-    auto encoding = requiredString("encoding");
-    if (!encoding) {
-      return unexpected(encoding.error());
-    }
-    d.encoding = *encoding;
-  } else {
-    auto encoding = optionalString("encoding");
-    if (!encoding) {
-      return unexpected(encoding.error());
-    }
-    d.encoding = *encoding;
+  auto encoding = readStringArray(j, "encoding");
+  if (!encoding) {
+    return unexpected(encoding.error());
+  }
+  if (family == PluginFamily::kMessageParser && encoding->empty()) {
+    return unexpected(std::string("plugin embedded manifest missing required encoding array"));
   }
+  d.encoding = std::move(*encoding);
 
   return d;
 }

pj_plugins/src/plugin_runtime_catalog.cpp

@@ -226,9 +226,7 @@ bool PluginRuntimeCatalog::loadAndRegisterMessageParser(const PluginDescriptor&
   loaded.id = descriptor.id;
   loaded.name = descriptor.name;
   loaded.version = descriptor.version;
-  if (!descriptor.encoding.empty()) {
-    loaded.encodings.push_back(descriptor.encoding);
-  }
+  loaded.encodings.insert(loaded.encodings.end(), descriptor.encoding.begin(), descriptor.encoding.end());
 
   report(DiagnosticLevel::kInfo, loaded.id, "Loaded MessageParser " + loaded.name + " from " + loaded.path);
   message_parsers_.push_back(std::move(loaded));

pj_plugins/tests/plugin_catalog_test.cpp

@@ -70,7 +70,7 @@ TEST_F(PluginCatalogTest, InspectMessageParserRequiresEncoding) {
   ASSERT_TRUE(descriptor.has_value()) << descriptor.error();
   EXPECT_EQ(descriptor->id, "mock-json-parser");
   EXPECT_EQ(descriptor->family, PluginFamily::kMessageParser);
-  EXPECT_EQ(descriptor->encoding, "json");
+  EXPECT_EQ(descriptor->encoding, std::vector<std::string>{"json"});
 }
 
 TEST_F(PluginCatalogTest, InspectToolboxDsoUsesEmbeddedManifest) {