Add new --follow mode for tower apps logs with resilient streaming and tests

[burakdede]

Addresses improvement required #164

• Add --follow to tower apps logs with SSE streaming, retry/backoff, Ctrl+C handling, dedupe across reconnects, and fatal‑error exits.
• Surface log-stream warnings and harden reconnection behavior (follow up commits for cancels stale monitors, explicit terminal status handling...).
• Add unit tests for parsing, terminal statuses, backoff, dedupe, and out‑of‑order logs.
• Extend mock API to emit warning SSE events and add an integration scenario to validate warning visibility.

Tests should cover most of the critical aspects of the implementation but I have also simulated some tests via local tower build and deploying app for;

• Synthetic logs (ticks + WARN/ERROR/JSON heartbeat) to validate live streaming, reconnect catch‑up, and clean exit.
• Verified broken‑pipe behavior Piping logs/JSON to a consumer that exits triggers Broken pipe and CLI panic #162 still fails when piping to head (known issue).

Drain Logs & Clean Exit

2026-01-15 19:10:03 | tick=48 time=2026-01-15T19:10:03.529504Z
2026-01-15 19:10:04 | tick=49 time=2026-01-15T19:10:04.529650Z
2026-01-15 19:10:05 | tick=50 time=2026-01-15T19:10:05.529810Z
2026-01-15 19:10:05 | WARN synthetic warning tick=50 time=2026-01-15T19:10:05.529810Z
2026-01-15 19:10:05 | ERROR synthetic error tick=50 time=2026-01-15T19:10:05.529810Z
2026-01-15 19:10:06 | tick=51 time=2026-01-15T19:10:06.529973Z
2026-01-15 19:10:07 | tick=52 time=2026-01-15T19:10:07.530149Z
2026-01-15 19:10:08 | tick=53 time=2026-01-15T19:10:08.530332Z
2026-01-15 19:10:09 | tick=54 time=2026-01-15T19:10:09.530482Z
2026-01-15 19:10:10 | tick=55 time=2026-01-15T19:10:10.530652Z
2026-01-15 19:10:10 | WARN synthetic warning tick=55 time=2026-01-15T19:10:10.530652Z
2026-01-15 19:10:11 | tick=56 time=2026-01-15T19:10:11.530797Z
Warning: No new logs available

Intermittent Failure Results & Slightly-Graceful Exit

2026-01-15 19:21:06 | WARN synthetic warning tick=85 time=2026-01-15T19:21:06.018685Z
2026-01-15 19:21:07 | tick=86 time=2026-01-15T19:21:07.018867Z
2026-01-15 19:21:08 | tick=87 time=2026-01-15T19:21:08.019028Z
2026-01-15 19:21:09 | tick=88 time=2026-01-15T19:21:09.019180Z
2026-01-15 19:21:10 | tick=89 time=2026-01-15T19:21:10.019344Z
2026-01-15 19:21:11 | tick=90 time=2026-01-15T19:21:11.020777Z
2026-01-15 19:21:11 | WARN synthetic warning tick=90 time=2026-01-15T19:21:11.020777Z
2026-01-15 19:21:11 | ERROR synthetic error tick=90 time=2026-01-15T19:21:11.020777Z
2026-01-15 19:21:11 | {"event":"heartbeat","tick":90,"time":"2026-01-15T19:21:11.020777Z"}
2026-01-15 19:21:12 | tick=91 time=2026-01-15T19:21:12.020962Z
2026-01-15 19:21:13 | tick=92 time=2026-01-15T19:21:13.021117Z
2026-01-15 19:21:14 | tick=93 time=2026-01-15T19:21:14.021280Z
2026-01-15 19:21:15 | tick=94 time=2026-01-15T19:21:15.021446Z
2026-01-15 19:21:16 | tick=95 time=2026-01-15T19:21:16.021620Z
2026-01-15 19:21:16 | WARN synthetic warning tick=95 time=2026-01-15T19:21:16.021620Z
2026-01-15 19:21:17 | tick=96 time=2026-01-15T19:21:17.021776Z
Oh no! Failed to monitor run completion after repeated errors
Oh no! The Tower CLI wasn't able to talk to the Tower API! Are you offline? Try again later.
Error: Fetching run details failed

Kill Log Stream & Clean Exit

2026-01-15 19:09:50 | WARN synthetic warning tick=35 time=2026-01-15T19:09:50.527412Z
2026-01-15 19:09:51 | tick=36 time=2026-01-15T19:09:51.527581Z
2026-01-15 19:09:52 | tick=37 time=2026-01-15T19:09:52.527723Z
2026-01-15 19:09:53 | tick=38 time=2026-01-15T19:09:53.527879Z
2026-01-15 19:09:54 | tick=39 time=2026-01-15T19:09:54.528027Z
2026-01-15 19:09:55 | tick=40 time=2026-01-15T19:09:55.528179Z
2026-01-15 19:09:55 | WARN synthetic warning tick=40 time=2026-01-15T19:09:55.528179Z
2026-01-15 19:09:55 | ERROR synthetic error tick=40 time=2026-01-15T19:09:55.528179Z
2026-01-15 19:09:56 | tick=41 time=2026-01-15T19:09:56.528346Z
2026-01-15 19:09:57 | tick=42 time=2026-01-15T19:09:57.528500Z
2026-01-15 19:09:58 | tick=43 time=2026-01-15T19:09:58.528661Z
2026-01-15 19:09:59 | tick=44 time=2026-01-15T19:09:59.528807Z
2026-01-15 19:10:00 | tick=45 time=2026-01-15T19:10:00.528944Z
2026-01-15 19:10:00 | WARN synthetic warning tick=45 time=2026-01-15T19:10:00.528944Z
2026-01-15 19:10:00 | {"event":"heartbeat","tick":45,"time":"2026-01-15T19:10:00.528944Z"}
2026-01-15 19:10:01 | tick=46 time=2026-01-15T19:10:01.529202Z
2026-01-15 19:10:02 | tick=47 time=2026-01-15T19:10:02.529351Z
2026-01-15 19:10:03 | tick=48 time=2026-01-15T19:10:03.529504Z
^CReceived Ctrl+C, stopping log streaming...
Note: The run will continue in Tower cloud
  See more: https://app.tower.dev/tastey-engine-877/default/apps/follow-logs-test-1768503576/runs/4