Fix shellv2 history loading and ordering

[KCarretto]

This PR fixes an issue where shell history was not displayed or was delayed when connecting to a ShellV2 session, particularly in interactive mode.

Changes:

1. Immediate Polling: The pollForShellTasks function is now called once before the main event loop in writeMessagesFromShell. This ensures that any existing shell tasks (history) are fetched and sent to the client immediately upon connection, rather than waiting for the first ticker event (which could be delayed or skipped in interactive mode).
2. Ordered History: The database query for shell tasks now explicitly orders results by created_at in ascending order. This guarantees that the command history is displayed in the correct sequence.
3. Regression Test: A new integration test TestShellHistory_Interactive has been added to tavern/internal/http/shell/integration_test.go. This test verifies that a client connecting to a shell with existing history receives that history immediately, even if the shell is in interactive mode (active portal).

Verification:

• Ran go test -v tavern/internal/http/shell/integration_test.go and verified that the new test case passes, along with existing tests.

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PR created automatically by Jules for task 10825082860140443234 started by @KCarretto

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[github-actions]

Summary

Tests 📝	Passed ✅	Failed ❌	Skipped ⏭️	Other ❓	Flaky 🍂	Duration ⏱️
2691    ±0	2691    ±0	0    ±0	0    ±0	0    ±0	0    ±0	1ms    ±0

Previous Results

Build 🏗️	Result 🧪	Tests 📝	Passed ✅	Failed ❌	Skipped ⏭️	Other ❓	Flaky 🍂	Duration ⏱️
#1317	✅	2691	2691	0	0	0	0	43.9s

Insights

Average Tests per Run	Total Flaky Tests	Total Failed	Slowest Test (p95)
2691	0	0	5.5s

Slowest Tests

Test 📝	Results 📊	Duration (avg) ⏱️	Duration (p95) ⏱️
TestDockerExecutor_Build_ContextCancellation	1	5.5s	5.5s
eldritch-libsys: std::dll_inject_impl::tests::test_dll_inject_simple	1	5.2s	5.2s
TestInteractiveShell	1	5.1s	5.1s
TestOtherStreamOutput	1	5.0s	5.0s
imix::bin/imix: install::tests::test_install_execution	3	1.6s	4.8s
imix::bin/imix: install::tests::test_install_execution	3	1.6s	4.8s
imix::bin/imix: install::tests::test_install_execution	3	1.6s	4.8s
imix::bin/imix: tests::task_tests::test_task_streaming_output	3	3.0s	3.0s
imix::bin/imix: tests::task_tests::test_task_streaming_output	3	3.0s	3.0s
imix::bin/imix: tests::task_tests::test_task_streaming_output	3	3.0s	3.0s

_{🎉 No failed tests in this run. | 🍂 No flaky tests in this run.}

Github Test Reporter by CTRF 💚