feat: mark progress with events (not prints)

[awadell1]

Excises print statements from agents and tools and replaces them with LangGraph events.
This gives the following wins:

1. Customized Display: the CLI/dashboard can now customize how progress is surfaced to the user
2. Observability: events can be logged to disk (and / or displayed) making it way easier to track what URSA did

The downsides:

• Events aren't printed by default (so nothing is surfaced, this mainly effects the python interface)

• Callback code can get rather entangled with the rest of the Agent code (see src/cli/callbacks.py)

• feat: add reusable agent event tagging

• feat: emit progress events from agents

• feat: emit progress events from tools

• feat: render hitl tool progress callbacks

[mikegros]

I saw that you made some updates, is this ready for review and did some of those changes reduce those downsides?

[awadell1]

Partially, ursa-dashboard now has uses the HITL callbacks and plan_execute_from_yaml does retain graphics for it's progress.

There's a default callback handler in, but it hasn't been fully patched into the examples

[mikegros]

A couple things:

I think this is ready to merge, but I wanted to bring up a couple things I noticed:

• There still seems to be some console.print-ing happening (at least in the write code tool) that seems to duplication some prints with the events:

ursa> execute make a png with a plot of the first 2100 prime number spacings
✏️ Writing file: prime_spacings.py
Writing file: prime_spacings.py

 ✔  File written: /path/to/workspace/prime_spacings.py
✅ File written: prime_spacings.py

• I saw some 404 errors in the web server logs for the dashboard, so am a bit worried something was being dropped/missed:

INFO:     127.0.0.1:51037 - "GET /runs/01KPXPY5M6X9RD82C871T5JWFG/events?after_seq=0&limit=5000 HTTP/1.1" 404 Not Found
INFO:     127.0.0.1:50967 - "GET /sessions/01KPXPST4Q9NTC22Q8375KCAQN/workspace HTTP/1.1" 200 OK
INFO:     127.0.0.1:51144 - "GET /runs/01KRN71S2P3XG2WY0NMBCCY6TC/events?after_seq=0&limit=5000 HTTP/1.1" 200 OK
INFO:     127.0.0.1:51037 - "GET /sessions/01KPXPST4Q9NTC22Q8375KCAQN HTTP/1.1" 200 OK
INFO:     127.0.0.1:51144 - "GET /runs/01KPXPY5M6X9RD82C871T5JWFG/events?after_seq=0&limit=5000 HTTP/1.1" 404 Not Found
INFO:     127.0.0.1:51037 - "GET /sessions/01KPXPST4Q9NTC22Q8375KCAQN/workspace HTTP/1.1" 200 OK
INFO:     127.0.0.1:51144 - "GET /runs/01KRN71S2P3XG2WY0NMBCCY6TC/events?after_seq=0&limit=5000 HTTP/1.1" 200 OK

I dont think this needs to hold things up much but thought I'd touch base with you first.