fix blog tag clicks, and new post

app/lib/firehose_web/controllers/blog_html/show.html.heex

@@ -1,4 +1,4 @@
 <div class="space-y-8">
   <a href={@base_path} class="text-sm text-primary hover:underline">&larr; Back to posts</a>
-  <.post_show post={@post} />
+  <.post_show post={@post} base_path={@base_path} />
 </div>

app/lib/firehose_web/controllers/blog_html/tag.html.heex

@@ -4,7 +4,7 @@
     <p class="mt-2 text-base-content/70">Posts tagged "{@tag}"</p>
   </header>
 
-  <.post_index posts={@posts} base_path={@base_path} />
+  <.post_index posts={@posts} base_path={@base_path} current_tag={@tag} />
 
   <a href={@base_path} class="text-sm text-primary hover:underline">&larr; All posts</a>
 </div>

app/priv/blog/engineering/2026/03-16-hello-world.md

@@ -1,6 +1,7 @@
 %{
   title: "Hello World",
   author: "Firehose Team",
+  published: false,
   tags: ~w(elixir phoenix),
   description: "Our first engineering blog post"
 }

app/priv/blog/engineering/2026/03-20-llm-simple-play.md

@@ -0,0 +1,13 @@
+
+%{
+  title: "Coding agent from scratch - a loop with tools, not that complicated",
+  author: "Willem van den Ende",
+  published: True,
+  tags: ~w(llm coding-agent python exercise),
+  description: "Coding agents are not that complicated. A loop with some tools. I found an interactive tutorial that lets you experience it"
+}
+---
+
+I had started on a "Write your own coding agent" exercise. Four iterations in, actually. And then I found [Tiny Agents]( https://tinyagents.dev/lesson/agent-loop), a set of interactive exercises that let you experience how agents work, from a simple chat request, through a tool, more tools etc. It has a live graph, that visualises of the flow of data and actions.
+
+It is good fun to play with, it starts simple and builds up. It lets you inspect the messages between the 'agent' loop code and the large language model server (which is just HTTP and some JSON).

app/test/firehose_web/controllers/blog_tags_test.exs

@@ -0,0 +1,123 @@
+defmodule FirehoseWeb.BlogTagsTest do
+  use FirehoseWeb.ConnCase
+
+  defp goto_engineering_tag_page(conn, tag) do
+    path = "/blog/engineering/tag/#{tag}"
+    conn = get(conn, path)
+    body = html_response(conn, 200)
+    assert body =~ ~s(tagged "#{tag}")
+    assert body =~ "Engineering Blog"
+    body
+  end
+
+  defp goto_releases_tag_page(conn, tag) do
+    path = "/blog/releases/tag/#{tag}"
+    conn = get(conn, path)
+    body = html_response(conn, 200)
+    assert body =~ ~s(tagged "#{tag}")
+    assert body =~ "Release Notes"
+    body
+  end
+
+  describe "engineering blog tags" do
+    test "GET /blog/engineering/tag/:tag shows tag page with all posts", %{conn: conn} do
+      body = goto_engineering_tag_page(conn, "elixir")
+      assert body =~ "Hello World"
+    end
+
+    test "GET /blog/engineering/tag/:tag page shows filtered posts", %{conn: conn} do
+      body = goto_engineering_tag_page(conn, "phoenix")
+      assert body =~ "Hello World"
+    end
+
+    test "GET /blog/engineering/tag/:tag page shows empty list for nonexistent tag", %{
+      conn: conn
+    } do
+      body = get(conn, "/blog/engineering/tag/nonexistent-tag")
+      assert html_response(body, 200) =~ ~s(tagged "nonexistent-tag")
+    end
+  end
+
+  describe "release notes blog tags" do
+    test "GET /blog/releases/tag/:tag shows tag page with all posts", %{conn: conn} do
+      body = goto_releases_tag_page(conn, "release")
+      assert body =~ "v0.1.0 Released"
+    end
+
+    test "GET /blog/releases/tag/:tag page shows filtered posts", %{conn: conn} do
+      body = get(conn, "/blog/releases/tag/nonexistent-tag")
+      assert html_response(body, 200) =~ ~s(tagged "nonexistent-tag")
+    end
+  end
+
+  describe "tag URL pattern" do
+    test "tag URLs follow pattern /blog/:blog_id/tag/:tag for engineering blog", %{conn: conn} do
+      # Test that the tag route exists and works correctly
+      conn = get(conn, "/blog/engineering/tag/elixir")
+      assert html_response(conn, 200) =~ ~s(tagged "elixir")
+
+      conn = get(conn, "/blog/engineering/tag/phoenix")
+      assert html_response(conn, 200) =~ ~s(tagged "phoenix")
+    end
+
+    test "tag URLs follow pattern /blog/:blog_id/tag/:tag for releases blog", %{conn: conn} do
+      # Test that the tag route exists and works correctly
+      conn = get(conn, "/blog/releases/tag/release")
+      assert html_response(conn, 200) =~ ~s(tagged "release")
+    end
+
+    test "nonexistent tags return 200 with empty post list", %{conn: conn} do
+      conn = get(conn, "/blog/engineering/tag/nonexistent-tag")
+      assert html_response(conn, 200)
+    end
+  end
+
+  describe "tag page structure" do
+    test "tag page has proper layout and back link", %{conn: conn} do
+      body = goto_engineering_tag_page(conn, "elixir")
+
+      assert body =~ "Engineering Blog"
+      assert body =~ ~s(tagged "elixir")
+      assert body =~ "All posts"
+    end
+
+    test "release tag page has proper layout and back link", %{conn: conn} do
+      body = goto_releases_tag_page(conn, "release")
+
+      assert body =~ "Release Notes"
+      assert body =~ ~s(tagged "release")
+      assert body =~ "All posts"
+    end
+  end
+
+  describe "clickable tags on index page" do
+    test "tags are rendered as clickable links on engineering blog index", %{
+      conn: conn
+    } do
+      conn = get(conn, "/blog/engineering")
+      body = html_response(conn, 200)
+
+      # Verify tag links exist with correct href pattern
+      assert body =~ ~r{href="/blog/engineering/tag/meta"}
+      assert body =~ ~r{href="/blog/engineering/tag/ai"}
+    end
+
+    test "tags are rendered as clickable links on releases blog index", %{
+      conn: conn
+    } do
+      conn = get(conn, "/blog/releases")
+      body = html_response(conn, 200)
+
+      # Verify tag link exists
+      assert body =~ ~r{href="/blog/releases/tag/release"}
+    end
+
+    test "tag links have proper styling classes", %{conn: conn} do
+      conn = get(conn, "/blog/engineering")
+      body = html_response(conn, 200)
+
+      # Verify blogex-tag-link class is present for tag links
+      assert body =~ ~r{class="[^"]*blogex-tag-link}
+    end
+  end
+end