Update the external libraries and refresh the documentation

CLAUDE.md

@@ -36,9 +36,10 @@ nuget restore RandomNumberGenerator.sln
 & $vstest "RandomNumberGenerator.Test\bin\Debug\Random Number Generator.Test.dll" /TestCaseFilter:"TestCategory=Component"
 ```
 
-Build ordering matters: post-build events copy the app output to `<sln>\bin\`, and the test project copies
-`<sln>\bin\TruRNGpro.dll` into its own output. Build the whole solution (not just the test project) or any
-test that reaches the P/Invoke layer will fail to load the native DLL.
+Build ordering matters. The native project copies `TruRNGpro.dll` to `<sln>\bin\`, and both the app and the
+test project copy it from there into their own output, because a native DLL is looked for beside the
+executable that loads it. Build the whole solution — building either managed project alone leaves the DLL
+missing and anything reaching the P/Invoke layer fails with `DllNotFoundException`.
 
 App output: `bin\Debug\Random Number Generator.exe` (also copied to `<sln>\bin\`).
 
@@ -73,21 +74,44 @@ sentinel.
 
 ### Session data model
 `RNGSessionData` keeps a bounded `ConcurrentQueue<double>` (`DataWindowSize`, default 6144, overwritten from
-`RNGChart.MaxDataSize` at form construction). Stats (average, mean deviation, standard deviation) are
-recomputed on every point; the queue is walked under `m_DataLock` even though it is concurrent, and scalars
-are published with `Interlocked.Exchange`.
+`RNGChart.MaxDataSize` — 1,024,000 — at form construction). Stats (average, mean deviation, standard
+deviation) are recomputed by walking the whole window: once per point while recording, but only once per
+batch in `LoadDataPointsBatch`, which is what keeps loading a large file from taking time that grows with
+the square of its size. The queue is walked under `m_DataLock` even though it is concurrent, and scalars are
+published with `Interlocked.Exchange`.
+
+Recording therefore costs a walk of the window per reading, reaching about 10% of the 100 ms interval once
+the window is full — around 28 hours of recording. Removing that needs rolling sums, which change the
+computed values and are deliberately not done; `MaxPoint`/`MinPoint` return `double.NaN` when there is no
+data rather than throwing.
 
 ### File format and append semantics
 Session files are XML: a single `<Session Simulated="true" Target="0">` element containing
 `<Data Time="hh:mm:ss">0.123</Data>` children. Element/attribute names live in `XMLConstants` — use them
 rather than string literals.
 
+Values are written and parsed with the invariant culture, so a file written where the decimal separator is a
+comma reads back as the same numbers elsewhere. `Target="-1"` means no target; `TargetValues.NO_VALUE_SET`
+(-2) is internal and is never written to a file.
+
 Loading an existing file (`RNGSessionData.LoadSession` → `RNGSessionDataFile.LoadSession` →
 `RNGXMLReader.LoadFile`) streams data points in batches through `LoadDataPointsBatch`, which fires the same
 `DataPointAddedCallback` so the chart fills in as it loads. Afterwards `RNGXMLWriter.PrepareForAppend`
-rewrites the file **textually** — truncating at the last `</Session>`, or converting a self-closing
-`<Session … />` into an open tag — so writing can resume. Changes to the session element shape must keep
-that text surgery in sync.
+edits the file **textually** so writing can resume, handling three shapes:
+
+1. a closed session, where the closing tag and the whitespace before it are truncated away;
+2. an empty session that closed itself, where `<Session … />` is reopened;
+3. a session left unterminated by the application stopping, where anything after the last complete
+   `</Data>` is discarded so a half-written element cannot be appended to.
+
+Only the ends of the file are read rather than the whole of it, because these files grow by roughly 2MB an
+hour. Changes to the session element shape must keep that text surgery in sync.
+
+A file of the third shape is what an interrupted session leaves, and it is recovered rather than rejected:
+the reader keeps every complete data point, refuses a partially written one, and reports the recovery
+through `LastError`, which the form shows to the user. A file that closes its session and still fails to
+parse is damaged rather than unfinished and is rejected as before. The two are told apart by the shape of
+the file, not by the parse error.
 
 ### GUI
 `GeneratorForm` is a state machine over `RngGuiStates` (Idle / Running / Paused / Terminating); the
@@ -126,7 +150,10 @@ here (`DeviceInterfaces` supplies the `USBDeviceNotification` constants used in
 `TruRNGpro/CODING_GUIDELINES_CPP.md` (native) are authoritative and are actually followed throughout. The
 non-obvious rules new code is expected to match:
 
-- Standardized file header block on every file (name, description, copyright, revision history).
+- Standardized file header block on every file: name, description, copyright, the MIT licence pointer, and
+  revision history. The templates in the three guidelines documents are the ones to copy. The name in the
+  header has to match the file it is in; two headers naming the file they were copied from have already had
+  to be corrected.
 - Modified Hungarian notation: `m_` + type char for members (`m_sFilePath`, `m_iPort`, `m_bValid`,
   `m_Timer` for objects), and `s`/`i`/`f`/`b` prefixes on locals.
 - `#region` blocks in a fixed order: Type definitions, Constructors, Event Handlers, Methods, Properties,
@@ -141,3 +168,20 @@ non-obvious rules new code is expected to match:
   swallowing and returning `false`; the form catches them and renders via `SetStatusBoxError`.
 - Tests: `[ClassName]Tests`, `[Method]_[Scenario]_[ExpectedResult]`, banner-commented Arrange/Act/Assert
   sections, Moq for collaborators, `[TestCategory("Component")]`.
+
+## Licence
+
+MIT, in `LICENSE`. Every source file carries the copyright line and a pointer to it. `TruRNGpro/rng.h` is
+third-party and is not covered by it; leave its header alone.
+
+## Releasing
+
+`.github/workflows/release.yml`, started by hand from the Actions tab and from `master` only. It refuses to
+run unless `RELEASE` is typed into the confirmation box, the version reads like `1.2.3` and has not been
+released before; it stops if the tests fail or the package is missing the application or the native
+library. What it produces is a **draft** release, so nothing is tagged or published without someone
+pressing publish.
+
+The unit tests do not build the form's event wiring, so a fault in it passes them: the crash that made
+loading a session file impossible was only found by driving the built application. Worth doing for changes
+that touch `GeneratorForm`.

README.md

@@ -142,8 +142,10 @@ The coding standards are written down and are followed throughout:
 
 - [Math.NET Numerics](https://numerics.mathdotnet.com/) (MIT), for the statistics
 - [Moq](https://github.com/devlooped/moq) and MSTest, for the tests
-- `Externals/CommonControls.dll` and `Externals/DeviceInterfaces.dll`, committed binaries with no source
-  in this repository
+- `Externals/CommonControls.dll` and `Externals/DeviceInterfaces.dll` (both MIT), built from
+  [CommonControls](https://github.com/Skorinn/CommonControls) and
+  [DeviceInterfaces](https://github.com/Skorinn/DeviceInterfaces). They are committed here as binaries
+  rather than built alongside this solution.
 - `TruRNGpro/rng.h`, a third-party header that wraps the serial port setup and reads for the device. It is
   not covered by this project's licence. Its author states in the file that it carries "No copyright, no
   warranties", which is a disclaimer rather than a formal grant such as CC0, so no particular legal status

RandomNumberGenerator.csproj

@@ -53,7 +53,7 @@
     <StartupObject>RandomNumberGenerator.Program</StartupObject>
   </PropertyGroup>
   <ItemGroup>
-    <Reference Include="CommonControls, Version=1.0.1.0, Culture=neutral, processorArchitecture=MSIL">
+    <Reference Include="CommonControls, Version=1.0.0.0, Culture=neutral, processorArchitecture=MSIL">
       <SpecificVersion>False</SpecificVersion>
       <HintPath>Externals\CommonControls.dll</HintPath>
     </Reference>