feat(community/agents): add AL agent quality guidance

- add 20 agent knowledge rules with good and bad AL samples
- clarify setup dialog shape, temporary persistence, permissions, profiles, instructions, capability registration, and interface wiring
- add the community-owned AL agents review skill
- make review fixture discovery layer-aware with custom, community, and Microsoft precedence
- document layer-aware evaluation behavior

community/knowledge/agents/reapply-resource-instructions-on-upgrade.md

@@ -0,0 +1,26 @@
+---
+bc-version: [27..]
+domain: agents
+keywords: [upgrade, setinstructions, navapp-getresourceastext, existing-instances, upgrade-tag]
+technologies: [al]
+countries: [w1]
+application-area: [all]
+---
+
+# Reapply resource instructions to existing agent instances on upgrade
+
+## Description
+
+Static instructions stored as an app resource are copied onto an instance only when you call `SetInstructions`. Shipping a new `Instructions.txt` in version 2.0 does not update agents created under 1.0. Models change the resource and assume running instances pick it up.
+
+## Best Practice
+
+In the upgrade codeunit, find existing instances of your metadata provider and call `SetInstructions` again with `NavApp.GetResourceAsText`. Guard with an upgrade tag so the rewrite runs once per version that changes the file.
+
+See sample: `reapply-resource-instructions-on-upgrade.good.al`.
+
+## Anti Pattern
+
+Editing only the resource file, or calling `SetInstructions` solely from the first-time setup path. Detection signal: instruction resource in `resourceFolders` with no upgrade procedure that re-applies it.
+
+See sample: `reapply-resource-instructions-on-upgrade.bad.al`.