Feature/alert muting

[HannahVernon]

What does this PR do?

Adds configurable muting of Alerts. For full description, plan, and concise change-log see #493

Which component(s) does this affect?

• [✅] Full Dashboard
• [✅] Lite Dashboard
• Lite Tests
• SQL collection scripts
• CLI Installer
• GUI Installer
• [✅] Documentation

How was this tested?

Manually tested both Dashboard and Lite per screenshots shown in #493

Checklist

• [✅] I have read the contributing guide
• [✅] My code builds with zero warnings (dotnet build -c Debug)
• [✅] I have tested my changes against at least one SQL Server version
• [✅] I have not introduced any hardcoded credentials or server names

[erikdarlingdata]

Code Review: Alert Muting

Overall this is well-structured with full parity across both apps. Nice work on the context-sensitive dialog, the auditability (muted alerts still logged), and the MCP integration. A few things to address:

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Bugs

1. [BLOCKER] DuckDB migration NOT NULL on ALTER TABLE
Lite/Database/DuckDbInitializer.cs:563 — The v20 migration uses BOOLEAN NOT NULL DEFAULT false, but DuckDB doesn't support NOT NULL on ALTER TABLE ADD COLUMN. There's even a comment in the v9 migration (line 424) warning about this exact issue. The catch block swallows the error so the column never gets added, and subsequent INSERTs that reference muted will fail.

Fix: Change to BOOLEAN DEFAULT false (drop the NOT NULL). The NOT NULL in Schema.CreateAlertLogTable for fresh installs is fine — this only affects the ALTER TABLE migration path.

2. "Mute This Alert" dialog title says "Edit Mute Rule"
Both Dashboard/Controls/AlertsHistoryContent.xaml.cs and Lite/Controls/AlertsHistoryTab.xaml.cs pass a pre-filled MuteRule to the MuteRuleDialog(MuteRule existingRule) constructor. Since existingRule != null, the dialog sets its title to "Edit Mute Rule" instead of "Create Mute Rule".

Fix: Either use the no-arg constructor and set fields after, add a bool isNew parameter, or use the AlertMuteContext constructor path.

3. "Mute This Alert" doesn't pre-fill context fields
Right-clicking an alert only pre-fills server name + metric name, not database/query text/wait type/job name. The AlertMuteContext constructor exists for rich pre-fill but is never called from the UI — the structured fields aren't on the display model. Users have to manually type pattern fields even though the detail info is visible in the alert.

This could be deferred to a follow-up, but worth noting the AlertMuteContext constructor is currently dead code.

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Medium

4. Lite MuteRuleService skips the LockedConnection pattern
All DuckDB operations in Lite/Services/MuteRuleService.cs call _dbInitializer.CreateConnection() directly without AcquireReadLock()/AcquireWriteLock(). The established pattern in LocalDataService uses locks to coordinate with CHECKPOINT and archive operations. A concurrent CHECKPOINT during a mute rule write could cause issues.

5. Cache-first, persist-second risks silent data loss
Lite's MuteRuleService mutates the in-memory cache under lock, then does a best-effort async DuckDB write. If the write fails silently, the user's changes are lost on next app restart since LoadAsync() reloads from DuckDB.

Consider: attempt the DB write first, update the cache only on success. Or at minimum log a visible warning when persistence fails.

6. Poison wait mute only checks worst wait type
Lite/MainWindow.xaml.cs:1195 — The mute context only includes worst.WaitType. If a user mutes RESOURCE_SEMAPHORE but THREADPOOL is the worst wait, the mute check evaluates THREADPOOL and the alert fires. If the muted wait happens to be worst, other unmuted waits get suppressed too. This is a design choice but may surprise users.

7. MCP tools gap

• get_alert_history in both apps doesn't include the new muted or detail_text columns
• get_mute_rules is missing from the README tools table (line 411)
• README tool counts (lines 49, 278) need incrementing

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Low / Cosmetic

8. Hardcoded color #33D97706 on MutedBanner in AlertDetailWindow — verify it looks right on Light/Cool Breeze themes.

9. Dashboard AlertDetailWindow missing Icon attribute (Lite sets /EDD.ico).

10. Dashboard MuteRuleService.Save() swallows all exceptions silently — should at least Logger.Error() them.

11. No automatic purge of expired rules — they accumulate until manual purge. Consider purging on startup in LoadAsync().

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What's Done Well

• All 7 alert metrics covered with consistent mute check pattern
• Muted alerts still logged for full auditability
• Thread safety via lock(_lock) with defensive ToList() copies
• All DuckDB queries properly parameterized (no SQL injection)
• Schema migrations idempotent with IF NOT EXISTS
• config_mute_rules correctly excluded from archivable tables
• Context-sensitive dialog hides irrelevant fields per metric type
• Clean settings integration entry point
• Schema test updated correctly

Bug #1 is a blocker for existing Lite users upgrading. The rest can be follow-up items if needed.

[HannahVernon]

PR Review Feedback — Changes Made (commit 7dc5744)

All 11 items from the review have been addressed. Here's a summary organized by severity:

Bug Fixes

1. [BLOCKER] DuckDB NOT NULL on ALTER TABLE (DuckDbInitializer.cs:563)
Changed v20 migration from BOOLEAN NOT NULL DEFAULT false to BOOLEAN DEFAULT false. DuckDB does not support NOT NULL on ALTER TABLE ADD COLUMN — this would crash on upgrade. Matches the pattern established in the v9 migration (line 424) which already had a comment about this limitation.

2. Dialog title showing "Edit" instead of "Create" (both editions)
Changed MuteThisAlert_Click in both AlertsHistoryContent.xaml.cs (Dashboard) and AlertsHistoryTab.xaml.cs (Lite) to construct MuteRuleDialog with an AlertMuteContext instead of a MuteRule. This uses the context-aware constructor which sets the title to "Create Mute Rule" and pre-fills available fields.

3. Context pre-fill / dead code (both editions)
By switching to the AlertMuteContext constructor (item #2 above), the pre-fill code path is now exercised — ServerName and MetricName are populated from the alert row. Richer field extraction from DetailText (database, query text, etc.) is deferred to a follow-up as suggested.

Medium Priority

4. Lite MuteRuleService — missing locked connections
Added AcquireReadLock() / AcquireWriteLock() to all DuckDB operations in Lite's MuteRuleService.cs, matching the LockedConnection pattern used throughout LocalDataService. This prevents CHECKPOINT from reorganizing the database file while mute rule operations are in progress.

5. Persist-first pattern (Lite MuteRuleService)
Restructured all mutation methods (AddRuleAsync, RemoveRuleAsync, UpdateRuleAsync, SetRuleEnabledAsync) to attempt the DB write first, then update the in-memory cache. Failures are logged via AppLogger.Warn() so the feature still works for the current session even if DuckDB persistence fails.

6. Poison wait mute limitation comment (both editions)
Added explanatory comment in both MainWindow.xaml.cs files (Dashboard line ~1390, Lite line ~1195) documenting that the mute check uses the worst triggered wait type, and that muting a non-worst type won't suppress the alert.

7. MCP tool gaps (both editions + README)

• Added muted and detail_text columns to get_alert_history results in both McpAlertTools.cs files
• Added get_mute_rules to the Alerts row in the README tools table
• Updated tool counts: Dashboard 27→28, Lite 31→32

Low Priority / Cosmetic

8. MutedBanner theme color (both editions)
Replaced hardcoded #33D97706 background with a theme-aware SolidColorBrush using {DynamicResource WarningColor} at 0.2 opacity in both AlertDetailWindow.xaml files. This ensures the muted banner renders correctly across Dark, Light, and CoolBreeze themes.

9. Dashboard AlertDetailWindow icon
Added Icon="/EDD.ico" to Dashboard/AlertDetailWindow.xaml to match the application icon shown on other windows.

10. Dashboard MuteRuleService.Save() error logging
Replaced silent catch {} with catch (Exception ex) { Helpers.Logger.Error(...) } in the Dashboard MuteRuleService.Save() method so persistence failures are logged.

11. Auto-purge expired rules on startup

• Dashboard: PurgeExpiredRules() is called after Load() in the MuteRuleService constructor
• Lite: PurgeExpiredRulesAsync() is called at the end of LoadAsync()

Files Changed (12 files, +112 / -65)

File	Changes
Dashboard/AlertDetailWindow.xaml	Icon, theme-aware MutedBanner
Dashboard/Controls/AlertsHistoryContent.xaml.cs	Use AlertMuteContext constructor
Dashboard/MainWindow.xaml.cs	Poison wait limitation comment
Dashboard/Mcp/McpAlertTools.cs	Add muted + detail_text columns
Dashboard/Services/MuteRuleService.cs	Error logging in Save(), auto-purge
Lite/Controls/AlertsHistoryTab.xaml.cs	Use AlertMuteContext constructor
Lite/Database/DuckDbInitializer.cs	Fix NOT NULL on v20 migration
Lite/MainWindow.xaml.cs	Poison wait limitation comment
Lite/Mcp/McpAlertTools.cs	Add muted + detail_text columns
Lite/Services/MuteRuleService.cs	Locked connections, persist-first, logging, auto-purge
Lite/Windows/AlertDetailWindow.xaml	Theme-aware MutedBanner
README.md	Tool counts, get_mute_rules in tools table

Build: 0 errors, 0 new warnings (all warnings are pre-existing). All 6 unit tests pass.