docs(CM0001): document the alcops.json load-failure warning

content/docs/analyzers/Common/CM0001.md

@@ -0,0 +1,40 @@
++++
+title = 'The ALCops configuration file could not be fully loaded'
+linkTitle = 'CM0001'
+
+[params]
+  id = 'CM0001'
+  severity = 'Warning'
+  category = 'Configuration'
+  codeAction = false
+  ignoreObsolete = false
++++
+
+`CM0001` warns when an [`alcops.json`](/docs/getting-started/configuration/) configuration file was found but could not be fully applied. Without this warning a broken configuration silently falls back to the default settings, and it can be hard to understand why your settings have no effect.
+
+The message names the file and the reason:
+
+```
+The ALCops configuration 'C:\Source\MyApp\alcops.json' could not be fully loaded: unknown setting 'CognitivComplexityThreshold'
+```
+
+### When it is reported
+
+| Situation | Effect on settings |
+|---|---|
+| The file exists but cannot be read (I/O or permission error) | Defaults are used |
+| The file contains invalid JSON (syntax error, wrong value type, unknown enum value) | Defaults are used |
+| The file is valid JSON but contains an unrecognized top-level setting (for example a typo in the name) | All recognized settings still apply; one warning per unknown setting |
+
+No warning is reported when no `alcops.json` exists — using the defaults without a configuration file is perfectly fine.
+
+### Notes
+
+- Setting names are matched case-insensitively, and the `$schema` key is always allowed.
+- The warning has no source location because `alcops.json` is not part of the compilation. Visual Studio Code shows such diagnostics against `app.json`.
+- An unreadable `alcops.json` in the app folder does **not** fall back to a configuration in a parent directory: the app-level file was intended to win, so ALCops uses the defaults and reports the problem instead.
+- Typos *inside* nested settings (for example a misspelled key under `StatementBlockSpacing`) are not detected by this rule; reference the [JSON schema](https://raw.githubusercontent.com/ALCops/Analyzers/main/src/ALCops.Common/Settings/alcops.schema.json) via `$schema` to have your editor validate those.
+
+### How to fix
+
+Open the `alcops.json` named in the message and correct the reported problem — fix the JSON syntax, correct the setting name, or resolve the file permission issue. The warning disappears once the file loads cleanly.

content/docs/analyzers/Common/_index.md

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+---
+title: "Common"
+type: docs
+no_list: true
+---
+
+Cross-cutting diagnostics from the shared `ALCops.Common` library. `ALCops.Common.dll` is loaded alongside every cop (it is part of every documented setup), so these diagnostics are reported once regardless of which cops you enable.
+
+## Rules
+
+| ID | Title | Severity | Enabled | Code Fix |
+|---|---|---|---|---|
+| [CM0001](cm0001/) | The ALCops configuration file could not be fully loaded | Warning | ✓ | |

content/docs/analyzers/_index.md

@@ -12,4 +12,5 @@ no_list: true
 | [FormattingCop](FormattingCop) | Enforces consistent code formatting and visual structure. |
 | [LinterCop](LinterCop) | Flags code quality issues, measures complexity, and promotes modern AL patterns. |
 | [PlatformCop](PlatformCop) | Detects code that is technically broken, dangerous, or silently ignored at the AL platform level. |
-| [TestAutomationCop](TestAutomationCop) | Validates the structure and correctness of AL test code. |
+| [TestAutomationCop](TestAutomationCop) | Validates the structure and correctness of AL test code. |
+| [Common](Common) | Cross-cutting diagnostics from the shared ALCops.Common library, loaded with every cop. |