[gx1400]

First part of #314 (spec F1.41).

Store (PacketHistory, MIT Core):

• What's kept: every packet the engine lists (received, sent, and same-source duplicates marked), with time, source, station or object, kind, position and the raw bytes.
• Where: one SQLite file per UTC day in history/ under the data folder, through Microsoft.Data.Sqlite. WAL, synchronous=NORMAL, no pooling.
• Writing: a bounded queue and a background writer that commits whatever has queued. Receiving never waits.
• Rotation: once a minute, and when the settings change, days past the length are deleted, then the oldest days past the size limit.
• Size warnings:
  • SizeLimitShortens, with "about N days fit", when the limit keeps fewer days than asked for. It's measured from whole days before they're trimmed.
  • TodayFull when today alone fills the limit. No more is kept until tomorrow.
  • The gateway also logs the warning once a day.
• Robustness: an unreadable day file is renamed .invalid and named in the status. A .lock file keeps a second engine on the same folder out (it shows InUseElsewhere).
• Deleting: turning history off and Start over delete it.

Settings:

• AppSettings.History (HistorySettings(Days, MaxMegabytes), default 7 days within 1,024 MB), validated as settings.history-invalid.
• [engine.history] days / max_megabytes in gateway.toml wins on every start, and Settings shows it without letting it be changed. The commented example is in deploy/linux/gateway.toml.
• IEngineService.GetHistoryStatusAsync, operator only on a gateway.

UI: Settings › Data › History, above capture. A switch, days, size, what's kept ("7 days kept, 412 MB, since …"), and the warning. Turning it off asks once more, because it deletes what's kept.

Not in this PR: the restart replay, long tracks and older packets, and the dashboard's 7 days. Those are the next PRs in the stack.

Checks:

• Tests: PacketHistoryTests (12) and HistoryUiTests (9), plus gateway access checks.
• Release build, all tests and csharpier pass locally.
• libe_sqlite3.so is in the linux-arm64 publish.

[github-actions]

Package report

Vulnerable packages

No known vulnerabilities in direct or transitive packages.

Available package updates

Package	Current version	Available version	Note
xunit.runner.visualstudio	3.1.5	4.0.1	Pinned in AprsMap.UI.Tests (see below)
xunit.v3.mtp-off	3.2.2	4.0.2	Pinned in AprsMap.UI.Tests (see below)

Pinned versions

These projects override the central version in Directory.Packages.props on purpose; updates for them are held back until the reason no longer applies.

Package	Pinned version	Project	Reason
xunit.runner.visualstudio	3.1.5	AprsMap.UI.Tests	Avalonia.Headless.XUnit 12.1 is built against xUnit v3 3.x and fails test discovery under 4.x (missing TestIntrospectionHelper overload). Pin this project only until Avalonia supports v4; see dependabot.yml.
xunit.v3.mtp-off	3.2.2	AprsMap.UI.Tests	Avalonia.Headless.XUnit 12.1 is built against xUnit v3 3.x and fails test discovery under 4.x (missing TestIntrospectionHelper overload). Pin this project only until Avalonia supports v4; see dependabot.yml.

_{Checked at 67c0aac against nuget.org.}