Let events affect incidents in multiple ways

[yhabteab]

Apart from the main changes, this PR also contains the following three additional commits that are not directly related to the referenced issue.

incident: update incident table only once & avoid superfluous copies

Previously, we've updated the incident table multiple times within the
very same transaction, and was clearly highlighted by the Go profiler.
Since the attributes aren't referenced anywhere else, we can just update
them in memory and only persist them to the database once at the end of
the transaction, which significantly eliminates a bunch of useless
upsert queries.

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event: add early return in `ExtractMissingRelations`

There's no need to retrieve a parser from pool to just immediately
release it if no filter columns were provided

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object: don't blindly copy all fields in `SyncFromEvent`

Instead of copying blindly all fields, we only need to update the fields
that were actually changed. For example, the tags field doesn't need to
be updated here, because if they've different tags, the ID would be
different, and thus we would have a different object in the cache. This
was highlighted by the Go profiler as one of the hotspots for memory
allocations, so don't update the fields that don't need to be updated.

Also, about the memory problems I had in Icinga Notifications, it was not a memory leak and there's no memory problems at all ;). It was consuming too much memory simply because I've built my containers with the -race flag, and after removing it, the daemon never goes beyond the 200MiB mark.

Requires

• Miscellaneous changes for Notifications icinga-go-library#212

fixes #261
resolves #407

[yhabteab]

Rebased and fixed some issues reported by Johannes offline.

[yhabteab]

Added some new basic testing for the ProcessEvent function in c69b2d7. This doesn't cover notifications but it's still better than nothing, I guess.

[Copilot]

Pull request overview

This PR updates the event/incident processing model to support multiple independent “effects” (open/escalate, close, mute/unmute, notify) in a more atomic way, and introduces persistence of the latest incident message (plugin output) on the incident itself.

Changes:

• Add incident.message column (PostgreSQL/MySQL) and persist incident message from incoming events.
• Rework incident processing to support combinations of incident/close/muted/notify, reduce redundant DB writes, and adjust HTTP validation/handling accordingly.
• Update object syncing and channel notification payloads to reduce copying and align with the updated event model/library dependency.

Reviewed changes

Copilot reviewed 13 out of 14 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
schema/pgsql/upgrades/incident-message.sql	Adds message column upgrade for PostgreSQL.
schema/pgsql/schema.sql	Adds message column to PostgreSQL incident schema.
schema/mysql/upgrades/incident-message.sql	Adds message column upgrade for MySQL.
schema/mysql/schema.sql	Adds message column to MySQL incident schema.
internal/object/object.go	Reduces copying in SyncFromEvent and updates only changed fields.
internal/listener/listener.go	Updates request preprocessing/validation flow and incomplete-relations handling based on OpenOrEscalate().
internal/incident/sync.go	Extends incident upsert shape to include message (but currently contains a critical bug).
internal/incident/incidents.go	Updates incident creation/closing logic and introduces stricter error mapping for invalid event combinations.
internal/incident/incidents_test.go	Refactors and expands incident behavior tests for new flags/flows.
internal/incident/incident.go	Implements new event-effect handling, notification triggering rules, message persistence, and close semantics.
internal/event/event.go	Delegates base validation to library, improves log marshaling, and adds early return in ExtractMissingRelations.
internal/channel/channel.go	Adjusts plugin notification event payload to match updated event fields.
go.mod	Updates icinga-go-library dependency revision.
go.sum	Updates checksums for the bumped icinga-go-library revision.

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[yhabteab]

Fixed the broken new unittests after the newest changes in Icinga/icinga-go-library#212 and ProcessEvent function accordingly.

[oxzi]

In general, LGTM. Thanks.

[oxzi]

🚣