feat: Gossamer migration — RuntimeBridge, gossamer.conf.json, Tauri→Gossamer conversion

Added Gossamer configuration and RuntimeBridge alongside existing Tauri setup.
Tauri files preserved for transition period.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: hyperpolymath

rescript-ecosystem/packages/bindings/gossamer/deno.json

@@ -0,0 +1,34 @@
+{
+  "name": "@hyperpolymath/rescript-gossamer",
+  "version": "0.1.0",
+  "exports": "./lib/es6/src/Gossamer.res.mjs",
+  "imports": {
+    "@rescript/core": "npm:@rescript/core@^1.0.0",
+    "rescript": "^12.0.0"
+  },
+  "tasks": {
+    "build": "deno run -A npm:rescript build",
+    "watch": "deno run -A npm:rescript build -w",
+    "clean": "deno run -A npm:rescript clean",
+    "test": "deno test --allow-read --allow-env test/",
+    "check": "deno check src/**/*.res.mjs"
+  },
+  "fmt": {
+    "include": [
+      "src/",
+      "test/"
+    ],
+    "exclude": [
+      "lib/"
+    ]
+  },
+  "lint": {
+    "include": [
+      "src/",
+      "test/"
+    ],
+    "exclude": [
+      "lib/"
+    ]
+  }
+}

rescript-ecosystem/packages/bindings/gossamer/rescript.json

@@ -0,0 +1,23 @@
+{
+  "name": "rescript-gossamer",
+  "sources": [
+    {
+      "dir": "src",
+      "subdirs": true
+    }
+  ],
+  "package-specs": [
+    {
+      "module": "esmodule",
+      "in-source": false
+    }
+  ],
+  "suffix": ".res.mjs",
+  "bs-dependencies": [
+    "@rescript/core"
+  ],
+  "bs-dev-dependencies": [],
+  "warnings": {
+    "number": "+A-48-42"
+  }
+}

rescript-ecosystem/packages/bindings/gossamer/src/Gossamer.res

@@ -0,0 +1,23 @@
+// SPDX-License-Identifier: PMPL-1.0-or-later
+// Copyright (c) 2026 Jonathan D.A. Jewell (hyperpolymath) <j.d.a.jewell@open.ac.uk>
+//
+// Gossamer.res — Top-level re-export module for rescript-gossamer bindings.
+//
+// Usage:
+//   open Gossamer
+//   let _ = Core.invoke("my_command")
+//   let _ = Dialog.openSingle()
+//   let _ = Fs.readTextFile("/path/to/file")
+//   let _ = Window.Current.closeCurrent()
+
+/// Core invoke and command bindings for Gossamer IPC.
+module Core = Gossamer_Core
+
+/// File picker, save, message, and confirmation dialog bindings.
+module Dialog = Gossamer_Dialog
+
+/// Filesystem operations (read, write, mkdir, stat, watch).
+module Fs = Gossamer_Fs
+
+/// Window management (resize, move, minimize, maximize, etc.).
+module Window = Gossamer_Window

rescript-ecosystem/packages/bindings/gossamer/src/bindings/Gossamer_Core.res

@@ -0,0 +1,131 @@
+// SPDX-License-Identifier: PMPL-1.0-or-later
+// Copyright (c) 2026 Jonathan D.A. Jewell (hyperpolymath) <j.d.a.jewell@open.ac.uk>
+//
+// Gossamer_Core.res — Core Gossamer invoke and command bindings.
+//
+// Provides the primary IPC bridge to the Gossamer runtime via
+// `window.__gossamer_invoke`. This is the Gossamer equivalent of
+// Tauri_Core.res (which wraps @tauri-apps/api/core).
+//
+// All Gossamer commands are dispatched through a single invoke function
+// injected by gossamer_channel_open() into the webview global scope.
+
+open RescriptCore
+
+// ============================================================================
+// Types
+// ============================================================================
+
+/// Invoke arguments — any JSON-serializable value.
+type invokeArgs = JSON.t
+
+/// Invoke options for customizing command calls.
+type invokeOptions = {
+  timeout?: int,
+  retries?: int,
+}
+
+/// Permission state for capability requests.
+type permissionState =
+  | @as("granted") Granted
+  | @as("denied") Denied
+  | @as("prompt") Prompt
+
+// ============================================================================
+// Runtime Detection
+// ============================================================================
+
+/// Check whether the Gossamer runtime is available in the current context.
+%%raw(`
+function isGossamerAvailable() {
+  return typeof window !== 'undefined'
+    && typeof window.__gossamer_invoke === 'function';
+}
+`)
+@val external isGossamerAvailable: unit => bool = "isGossamerAvailable"
+
+// ============================================================================
+// Core Invoke API
+// ============================================================================
+
+/// Raw invoke binding — calls window.__gossamer_invoke(cmd, args).
+/// This is the foundation for all Gossamer IPC.
+%%raw(`
+function gossamerInvokeRaw(cmd, args) {
+  if (typeof window !== 'undefined' && typeof window.__gossamer_invoke === 'function') {
+    return window.__gossamer_invoke(cmd, args);
+  }
+  return Promise.reject(new Error('Gossamer runtime not available'));
+}
+`)
+@val external invokeRaw: (string, 'a) => promise<'b> = "gossamerInvokeRaw"
+
+/// Invoke a Gossamer command with typed arguments and response.
+/// Commands are defined in the Gossamer backend (Rust/Zig) and
+/// exposed via the IPC channel.
+let invoke = (command: string, ~args: invokeArgs=?): promise<'response> => {
+  let finalArgs = switch args {
+  | Some(a) => a
+  | None => Obj.magic(Dict.make())
+  }
+  invokeRaw(command, finalArgs)
+}
+
+/// Invoke a command with automatic JSON serialization/deserialization.
+/// Use this when you want type safety on both request and response.
+let invokeTyped = async (
+  ~command: string,
+  ~args: 'args,
+  ~decoder: JSON.t => result<'response, string>,
+): result<'response, string> => {
+  try {
+    let response = await invokeRaw(command, args)
+    decoder(Obj.magic(response))
+  } catch {
+  | Exn.Error(err) =>
+    Error(Exn.message(err)->Option.getOr("Unknown Gossamer invoke error"))
+  }
+}
+
+// ============================================================================
+// App Info API
+// ============================================================================
+
+/// Get the application name from the Gossamer runtime.
+let getName = (): promise<string> => {
+  invokeRaw("__gossamer_app_get_name", {})
+}
+
+/// Get the application version from the Gossamer runtime.
+let getVersion = (): promise<string> => {
+  invokeRaw("__gossamer_app_get_version", {})
+}
+
+/// Get the Gossamer runtime version.
+let getGossamerVersion = (): promise<string> => {
+  invokeRaw("__gossamer_app_get_runtime_version", {})
+}
+
+/// Show the application window.
+let show = (): promise<unit> => {
+  invokeRaw("__gossamer_app_show", {})
+}
+
+/// Hide the application window.
+let hide = (): promise<unit> => {
+  invokeRaw("__gossamer_app_hide", {})
+}
+
+// ============================================================================
+// Capability API
+// ============================================================================
+
+/// Check if a capability is available.
+let hasCapability = (capability: string): promise<bool> => {
+  invokeRaw("__gossamer_capability_check", {"capability": capability})
+}
+
+/// Request a capability from the runtime.
+let requestCapability = (capability: string): promise<permissionState> => {
+  invokeRaw("__gossamer_capability_request", {"capability": capability})
+}