Name the Agents task counts so 150 / 0 / 128 are not one tile

[RainMona]

Fixes #20

Independent of #5 / #6 / #7 / #15 / #16 / #17 / #18 / #19. This PR is a new branch from origin/main only; it does not stack on those branches. #14 stays pressed.

What changed

On ?view=agents, Tasks / runs showed 150 / 0 with 128 current underneath. An idle desk (0 runs, 0 tokens) looked like a stalled queue.

The tile now has one headline number:

• Tasks 150
• detail 128 runnable · 0 runs

No run, campaign, dispatch, or claim CTA was added on this tile. No spend, signing, or funds path was added.

How to check

1. Open Studio at /?view=agents (do not start a run or campaign).
2. The third metric should read Tasks with a single headline count, not 150 / 0.
3. The detail should name runnable and runs separately.
4. Sidebar remains Analysis only · no execution.

Tests

• apps/studio/src/lib/agent-task-run-tile.test.ts — observed 150 / 0 / 128 becomes a single headline plus named detail

[RainMona]

Superseded by topic PR #43 (Desk copy and dispatch honesty). This small PR is folded into that branch from origin/main. Do not merge this one.