app-module events & callstack config, crash diagnostics (#630)

- Apps can specify task stack depth and preferred memory placement in their manifests.
- App identifiers are validated against length and character requirements.
- Crash diagnostics now show the crash cause, reason, fault address, call stack, and program-counter details, with logs saved for review.
- App closing is more consistent across built-in screens. There's now a dedicated function, and the old _emit() function is made private.
- Crash diagnostics no longer display a QR code without a call stack.
- Improved memory allocation for unrestricted requests.

Modules/app-module/private/app/private/event.h

@@ -0,0 +1,24 @@
+#pragma once
+
+#include <app/event.h>
+#include <app/instance.h>
+
+#include <tactility/error.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/**
+ * Deliver @a event to every subscription registered for @a app_instance_id (normally exactly one).
+ * @warning Does not work in ISR context.
+ * @retval ERROR_NONE delivered to at least one subscription
+ * @retval ERROR_NOT_FOUND no subscription is registered for @a app_instance_id
+ * @retval ERROR_RESOURCE at least one matching subscription's queue was full; the event was
+ * dropped for that subscription (still delivered to any other matching subscription)
+ */
+error_t app_event_emit(AppInstanceId app_instance_id, const struct AppEvent* event);
+
+#ifdef __cplusplus
+}
+#endif

Modules/app-module/private/app/private/metadata_parsing_internal.h

@@ -13,10 +13,10 @@
 bool app_metadata_get_value(const std::map<std::string, std::string>& properties, const std::string& key, std::string& out_value);
 
 bool app_metadata_is_valid_format_version(const std::string& version);
-bool app_metadata_is_valid_id(const std::string& id);
 bool app_metadata_is_valid_name(const std::string& name);
 bool app_metadata_is_valid_version_name(const std::string& version);
 bool app_metadata_is_valid_version_code(const std::string& version);
+bool app_metadata_is_valid_stack_size(const std::string& value);
 
 /** Validates a comma-separated list of device ids (alphanumeric + '-' items, matching Devices/<id> folder names). */
 bool app_metadata_is_valid_device_id_list(const std::string& value);
@@ -31,3 +31,5 @@ bool app_metadata_parse_v1(const std::map<std::string, std::string>& properties,
 
 /** Parses a V2 (flat dot-notation, e.g. "app.version.name=...") manifest map into @a out_metadata. */
 bool app_metadata_parse_v2(const std::map<std::string, std::string>& properties, struct AppMetadata& out_metadata);
+
+bool app_metadata_validate_string(const std::string& value, bool (*is_valid_char)(char));

Modules/app-module/private/app/private/scheduler.h

@@ -21,12 +21,13 @@ extern "C" {
  * AppLoaderApi::load()/run(), marking the instance ACTIVE for the duration of run().
  * @param[in] app_instance_id id already allocated in the ledger for this instance
  * @param[in] location the location of the app
+ * @param[in] stack stack allocation config for the app's task
  * @param[in] argc the amount of arguments to pass to the app's main function
  * @param[in] argv the array of arguments to pass to the app's main function - ownership is
  * taken by the scheduler regardless of outcome (freed once the spawned task's run() returns, or
  * immediately on a failure to start it)
  */
-error_t app_scheduler_start(AppInstanceId app_instance_id, struct AppLocation location, int argc, char* argv[]);
+error_t app_scheduler_start(AppInstanceId app_instance_id, struct AppLocation location, struct AppStackConfig stack, int argc, char* argv[]);
 
 /**
  * Permanently stops an app instance (APP_EVENT_CLOSE if it was running), bound-waits for its