feat: /tasks detail view + In Progress button

- /tasks number:26 shows full task detail embed
  (description, tags, status, priority, owner, dates)
- Mark Done, In Progress, and Take Task buttons on detail view
- task_progress_ button handler sets status to in_progress

Chronicler #78 | firefrost-services

services/arbiter-3.0/src/discord/tasks.js

@@ -49,6 +49,10 @@ const tasksCommand = new SlashCommandBuilder()
         { name: 'Done', value: 'done' },
         { name: 'Everything', value: 'all' }
       )
+  )
+  .addIntegerOption(option =>
+    option.setName('number')
+      .setDescription('View a specific task by number (e.g. 26)')
   );
 
 function isStaff(member) {
@@ -123,6 +127,84 @@ async function buildTaskEmbed(tasks, filterLabel) {
   return { embed, rows };
 }
 
+async function handleTaskDetail(interaction, taskNumber) {
+  try {
+    const result = await db.query(
+      'SELECT * FROM tasks WHERE task_number = $1',
+      [taskNumber]
+    );
+
+    if (result.rows.length === 0) {
+      return interaction.editReply(`❌ Task #${taskNumber} not found.`);
+    }
+
+    const t = result.rows[0];
+    const pri = PRIORITY_EMOJI[t.priority] || '⚪';
+    const sta = STATUS_EMOJI[t.status] || '⬡';
+
+    const embed = new EmbedBuilder()
+      .setTitle(`${sta} #${t.task_number} — ${t.title}`)
+      .setColor(
+        t.status === 'done' ? 0x22c55e :
+        t.status === 'blocked' ? 0xef4444 :
+        t.priority === 'critical' ? 0xef4444 :
+        t.priority === 'high' ? 0xff6b35 :
+        0x4ECDC4
+      )
+      .addFields(
+        { name: 'Status', value: `${sta} ${t.status}`, inline: true },
+        { name: 'Priority', value: `${pri} ${t.priority}`, inline: true },
+        { name: 'Owner', value: t.owner || 'unassigned', inline: true }
+      )
+      .setTimestamp(new Date(t.updated_at));
+
+    if (t.description) {
+      embed.setDescription(t.description.length > 400 ? t.description.substring(0, 400) + '...' : t.description);
+    }
+
+    if (t.tags && t.tags.length > 0) {
+      embed.addFields({ name: 'Tags', value: t.tags.map(tag => `\`${tag}\``).join(' '), inline: false });
+    }
+
+    if (t.completed_at) {
+      const completedDate = new Date(t.completed_at).toLocaleDateString('en-US', { month: 'short', day: 'numeric', year: 'numeric' });
+      embed.addFields({ name: 'Completed', value: `${completedDate}${t.completed_by ? ` by ${t.completed_by}` : ''}`, inline: false });
+    }
+
+    embed.setFooter({ text: `Created ${new Date(t.created_at).toLocaleDateString('en-US', { month: 'short', day: 'numeric' })} · Updated ${new Date(t.updated_at).toLocaleDateString('en-US', { month: 'short', day: 'numeric' })}` });
+
+    // Action buttons for active tasks
+    const rows = [];
+    if (t.status !== 'done' && t.status !== 'obsolete') {
+      const buttons = [
+        new ButtonBuilder()
+          .setCustomId(`task_done_${t.id}`)
+          .setLabel('Mark Done')
+          .setStyle(ButtonStyle.Success),
+        new ButtonBuilder()
+          .setCustomId(`task_progress_${t.id}`)
+          .setLabel('In Progress')
+          .setStyle(ButtonStyle.Primary)
+      ];
+      if (t.owner === 'unassigned') {
+        buttons.push(
+          new ButtonBuilder()
+            .setCustomId(`task_take_${t.id}`)
+            .setLabel('Take Task')
+            .setStyle(ButtonStyle.Secondary)
+        );
+      }
+      rows.push(new ActionRowBuilder().addComponents(buttons));
+    }
+
+    await interaction.editReply({ embeds: [embed], components: rows });
+
+  } catch (err) {
+    console.error('Task detail error:', err);
+    await interaction.editReply('❌ Error loading task details.');
+  }
+}
+
 async function handleTasksCommand(interaction) {
   if (!isStaff(interaction.member)) {
     return interaction.reply({
@@ -133,6 +215,12 @@ async function handleTasksCommand(interaction) {
 
   await interaction.deferReply();
 
+  // Check if viewing a specific task
+  const taskNumber = interaction.options.getInteger('number');
+  if (taskNumber) {
+    return handleTaskDetail(interaction, taskNumber);
+  }
+
   const filter = interaction.options.getString('filter') || 'open';
 
   try {
@@ -245,6 +333,32 @@ async function handleTaskButton(interaction) {
       await interaction.reply({ content: '❌ Error updating task.', ephemeral: true });
     }
   }
+
+  if (customId.startsWith('task_progress_')) {
+    const taskId = customId.replace('task_progress_', '');
+    const owner = ownerFromDiscord(interaction.member);
+
+    try {
+      const result = await db.query(
+        `UPDATE tasks SET status = 'in_progress', owner = $1, updated_at = NOW()
+         WHERE id = $2 RETURNING task_number, title`,
+        [owner, taskId]
+      );
+
+      if (result.rows.length > 0) {
+        const t = result.rows[0];
+        await interaction.reply({
+          content: `🔄 **#${t.task_number} — ${t.title}** marked in progress by ${owner}!`,
+          ephemeral: false
+        });
+      } else {
+        await interaction.reply({ content: '❌ Task not found.', ephemeral: true });
+      }
+    } catch (err) {
+      console.error('Task progress error:', err);
+      await interaction.reply({ content: '❌ Error updating task.', ephemeral: true });
+    }
+  }
 }
 
 module.exports = { tasksCommand, handleTasksCommand, handleTaskButton };