Add Notification Ent and associated GraphQL mutations

[KCarretto]

This PR adds the Notification Ent schema and its associated edges to User and Event. An Ent hook HookDeriveNotifications is created to generate notifications when quests complete or host access is new/recovered. Furthermore, it introduces markNotificationsAsRead and markNotificationsAsArchived GraphQL mutations. Tests have been added to verify functionality.

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PR created automatically by Jules for task 18102855642606691479 started by @KCarretto

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[github-actions]

Summary

Tests 📝	Passed ✅	Failed ❌	Skipped ⏭️	Other ❓	Flaky 🍂	Duration ⏱️
2944	2943	1	0	0	0	1ms

Previous Results

Build 🏗️	Result 🧪	Tests 📝	Passed ✅	Failed ❌	Skipped ⏭️	Other ❓	Flaky 🍂	Duration ⏱️
#2005	❌	2944	2943	1	0	0	0	493340h 38m

Insights

Average Tests per Run	Total Flaky Tests	Total Failed	Slowest Test (p95)
2944	0	1	4m 33s

Fail Rate

Fail Rate	0.03%

Test 📝	Results 📊	Passed ✅	Failed ❌	Fail Rate (%) 📈
TestMetrics_QuestTimelineChart	1	0	1	100.00    ↑100.00

Failed Tests

Failed Tests
❌ TestMetrics_QuestTimelineChart === RUN TestMetrics_QuestTimelineChart metrics_test.go:101: Error Trace: /home/runner/work/realm/realm/tavern/internal/graphql/metrics_test.go:101 Error: Not equal: expected: 1 actual : 0 Test: TestMetrics_QuestTimelineChart --- FAIL: TestMetrics_QuestTimelineChart (0.01s) Trace: No trace available

Test Changes

0 test added, 0 removed

Slowest Tests

Test 📝	Results 📊	Duration (avg) ⏱️	Duration (p95) ⏱️
eldritch-libfile: std::list_recent_impl::tests::test_list_recent_default_args	3	3m 6s	4m 33s
eldritch-libfile: std::list_recent_impl::tests::test_list_recent_default_args	3	3m 6s	4m 33s
eldritch-libfile: std::list_recent_impl::tests::test_list_recent_default_args	3	3m 6s	4m 33s
TestDockerExecutor_Build_ContextCancellation	1	6.1s	6.1s
eldritch-libsys: std::dll_inject_impl::tests::test_dll_inject_simple	1	5.2s	5.2s
TestInteractiveShell	1	5.0s	5.0s
TestOtherStreamOutput	1	5.0s	5.0s
TestDockerExecutor_Build_SimpleEcho	1	3.4s	3.4s
imix::bin/imix: tests::task_tests::test_task_streaming_error	3	3.0s	3.0s
imix::bin/imix: tests::task_tests::test_task_streaming_error	3	3.0s	3.0s

_{🍂 No flaky tests in this run.}

Github Test Reporter by CTRF 💚