Add CW keying, function key messages and the documentation

The function keys send through cwdaemon or a WinKeyer, with N1MM's message
macros. Escape stops sending.

Settings are read with the reflection serializer rather than a generated one:
the generated one hands back null for every property the file leaves out
instead of the value the property is declared with, which crashed the program
the first time a new setting was added.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

docs/n1mm-interop.md

@@ -0,0 +1,54 @@
+# Opening a Nonemm log in N1MM
+
+Checked on 2026-08-27 against N1MM Logger+ 1.0.11031 by writing a log here,
+copying it to a Windows machine and opening it there. N1MM read the contest, its
+categories and the contacts.
+
+Three things had to be right, and none of them is obvious from the schema.
+
+## The `Contest` table needs a row for the contest
+
+`ContestInstance` says which contest a log is; the `Contest` table says what that
+contest *is*. N1MM reads it in `Contest.FromRow` when it opens a log and throws
+`InvalidOperationException: No current row` if the row is missing, which reaches
+the operator as "A runtime error occurred".
+
+So the definition row is written whenever a contest is opened, not only when it
+is created — a log made before this was understood gets its row the next time it
+is opened. `ContestDefinitions.For` builds the row from the contest's own rules:
+the display and Cabrillo names, the mode, the dupe type and the multiplier
+names.
+
+## The overlay category cannot be empty
+
+An empty `ContestInstance.OverlayCategory` is answered with "Invalid Overlay
+Category:" and the log will not open. An entry with no overlay says `N/A`.
+
+N1MM's list is not the Cabrillo specification's list. N1MM offers:
+
+    N/A, ROOKIE, BAND-LIMITED, TB-WIRES, OVER-50, HQ, NOVICE-TECH, EXPERT
+
+so that is what the contest dialog offers.
+
+## The sent exchange omits the report
+
+N1MM's contest dialog says "Omit RST: CQWW: 05". `SentExchange` for CQ WW is
+`14`, not `599 14`; for a serial number contest it is `001`. The report is fixed
+for the whole contest and the entry window fills it in per contact.
+
+## Getting the schema in the first place
+
+N1MM ships no template database. `ham.s3db` is built at run time by applying SQL
+migration files that N1MM writes out from string resources inside
+`N1MMLogger.net.exe`. To read them: decompile the executable, parse
+`N1MMLogger.Net.Resources.resx`, and take the untyped `<data>` entries named
+`DXLogDDL_0001_initial_schema_and_data` through `DXLogDDL_0004_updates`. The QSO
+table is `DXLOG` and the current `PRAGMA user_version` is 4.
+
+`src/Nonemm.Storage/Schema.sql` is that schema, flattened to the state version 4
+leaves behind.
+
+## One thing to avoid
+
+Do not replace the database file under a running N1MM. It does not notice and
+throws on the next read.