[DISCORDSH] Implement Task Board embed generator

[h0lybyte]

Parent

Part of #7849

Description

Implement the Task Board embed generator that renders phase-based project tracking with per-department task breakdowns as rich Discord embeds.

Example Output

task_board_embed = discord.Embed(
    title="🧩 Task Board — Phase 0: Infrastructure Setup",
    description="Establish foundational infrastructure.",
    color=0x3498DB,
)
task_board_embed.add_field(name="Programming", value="• ***Task*** — **Owner** — ***Status: OPEN***", inline=False)
task_board_embed.add_field(name="3D Art", value="• ***Task*** — **Owner** — ***Status: OPEN***", inline=False)

Acceptance Criteria

• Generates embed from GitHub project/milestone data
• Groups tasks by department/label
• Shows status (OPEN, MERGED, CLOSED) per task
• Links back to GitHub repo