feat: Add model download button to Hugging Face website

Adds a button to the Hugging Face website allowing users to download models directly from the Page Assist extension. The button appears next to the copy snippet button on model pages. This allows users to easily pull models directly to their local machine for use with Ollama.

The button triggers a confirmation dialog, ensuring users understand the action before proceeding. The process leverages a background script to handle the actual download and displays a message during the download process.

src/entries/hf-pull.content.ts

@@ -0,0 +1,93 @@
+export default defineContentScript({
+  main(ctx) {
+    const downloadModel = async (modelName: string) => {
+      const ok = confirm(
+        `[Page Assist Extension] Do you want to pull the ${modelName} model? This has nothing to do with the huggingface.co website. The model will be pulled locally once you confirm. Make sure Ollama is running.`
+      )
+      if (ok) {
+        alert(
+          `[Page Assist Extension] Pulling ${modelName} model. For more details, check the extension icon.`
+        )
+
+        await browser.runtime.sendMessage({
+          type: "pull_model",
+          modelName
+        })
+        return true
+      }
+      return false
+    }
+
+    const downloadSVG = `
+        <svg xmlns="http://www.w3.org/2000/svg" fill="currentColor" viewBox="0 0 24 24" width="16" height="16">
+          <path d="M12 16l-6-6h4V4h4v6h4l-6 6z"/>
+          <path d="M4 20h16v-2H4v2z"/>
+        </svg>
+      `
+
+    const injectDownloadButton = (modal: HTMLElement) => {
+      const copyButton = modal.querySelector(
+        'button[title="Copy snippet to clipboard"]'
+      )
+      if (copyButton && !modal.querySelector(".pageassist-download-button")) {
+        const downloadButton = copyButton.cloneNode(true) as HTMLElement
+        downloadButton.classList.add("pageassist-download-button")
+        downloadButton.querySelector("svg")!.outerHTML = downloadSVG
+        downloadButton.querySelector("span")!.textContent =
+          "Pull from Page Assist"
+        downloadButton.addEventListener("click", async () => {
+          const preElement = modal.querySelector("pre")
+          if (preElement) {
+            let modelCommand = ""
+            preElement.childNodes.forEach((node) => {
+              if (node.nodeType === Node.TEXT_NODE) {
+                modelCommand += node.textContent
+              } else if (node instanceof HTMLSelectElement) {
+                modelCommand += node.value
+              } else if (node instanceof HTMLElement) {
+                const selectElement = node.querySelector(
+                  "select"
+                ) as HTMLSelectElement
+                if (selectElement) {
+                  modelCommand += selectElement.value
+                } else {
+                  modelCommand += node.textContent
+                }
+              }
+            })
+
+            modelCommand = modelCommand.trim()
+
+            await downloadModel(
+              modelCommand
+                ?.replaceAll("ollama run", "")
+                ?.replaceAll("ollama pull", "")
+                ?.trim()
+            )
+          }
+        })
+        copyButton.parentElement!.insertBefore(
+          downloadButton,
+          copyButton.nextSibling
+        )
+      }
+    }
+
+    const observer = new MutationObserver((mutations) => {
+      for (const mutation of mutations) {
+        mutation.addedNodes.forEach((node) => {
+          if (node instanceof HTMLElement) {
+            const modal = node.querySelector(".shadow-alternate") as HTMLElement
+            if (modal) {
+              injectDownloadButton(modal)
+            }
+          }
+        })
+      }
+    })
+
+    observer.observe(document.body, { childList: true, subtree: true })
+  },
+  allFrames: true,
+  matches: ["*://huggingface.co/*"]
+})