Expand review skills to match the 6-domain knowledge corpus

The knowledge corpus now covers performance, security, privacy, upgrade,
style, and UI. Previously only two leaf reviewer skills existed
(al-performance-review, al-security-review), so four of the six domains
had knowledge with no skill sourcing from them. A community reader
landing in privacy/, upgrade/, style/, or ui/ would see articles with
no apparent consumer.

Three changes:

1. Move existing review skills into `microsoft/skills/review/`. The
   `review/` subfolder groups all review-kind skills together and leaves
   room for future non-review action skills at the `microsoft/skills/`
   level. Updates references in README.md, agent-consumption.md, and
   skills/entry.md to the new paths.

2. Add four new leaf reviewer skills — al-privacy-review,
   al-upgrade-review, al-style-review, al-ui-review — each following
   the same DO template as al-performance-review/al-security-review but
   sourcing from the corresponding knowledge domain. al-upgrade-review
   and al-ui-review return `not-applicable` when the diff contains no
   upgrade surface or no page files, respectively.

3. Update al-code-review to compose all six leaf skills and retarget
   the dangling references in every populated JSON example
   (`use-setloadfields.md`, `no-plaintext-secrets-in-telemetry.md`,
   `avoid-implicit-commit.md` — none of which exist in the corpus) to
   real knowledge files: `call-setloadfields-before-filters.md`,
   `use-secrettext-for-credentials.md`, `never-hardcode-secrets-in-al.md`.

Validator passes with 0 errors / 0 warnings.

microsoft/skills/review/al-upgrade-review.md

@@ -0,0 +1,101 @@
+---
+kind: action-skill
+id: al-upgrade-review
+version: 1
+title: AL upgrade review
+description: Reviews AL source changes against upgrade-code and migration guidance from BCQuality.
+inputs: [pr-diff, file-path]
+outputs: [findings-report]
+bc-version: [all]
+technologies: [al]
+countries: [w1]
+application-area: [all]
+---
+
+# AL upgrade review
+
+Reviews AL source changes against the `upgrade` knowledge domain in BCQuality and emits a findings report. This is a leaf action skill: it invokes no sub-skills. It is one of the skills composed by `al-code-review`.
+
+An orchestrator invokes this skill with either a `pr-diff` (the standard PR-review entry point) or a `file-path` (single-file review). Upgrade findings are narrow by design — they apply when the diff touches upgrade codeunits, install codeunits, table schema, enums, or objects under migration namespaces. The skill returns `not-applicable` when none of those apply.
+
+## Source
+
+Collect all knowledge files under `*/knowledge/upgrade/**/*.md`, across every enabled layer (`/microsoft/`, `/community/`, `/custom/`). Relevance trims the result to the subset that applies.
+
+## Relevance
+
+Apply the frontmatter matching rules defined in READ (*Frontmatter matching semantics*) against the task context:
+
+- `bc-version` — the target BC version from the PR branch's `app.json` or the orchestrator-supplied version. If unavailable, the dimension is `unknown`.
+- `technologies` — `[al]`.
+- `countries` — the countries declared in the consuming app's `app.json`. Default to the orchestrator's configured context; if absent, `unknown`.
+- `application-area` — the union of application areas declared by the changed objects. Pass the actual set; do not substitute `[all]`. If the area cannot be determined from the changes, the dimension is `unknown`.
+
+Discard files that are not applicable. Retain conditionally applicable files (any dimension `unknown`) only when the orchestrator's configuration permits them; findings derived from those files MUST have `confidence` no higher than `medium`, AND the finding's `message` MUST name the dimension or dimensions that were unknown.
+
+## Worklist
+
+Narrow the relevant files to the subset that applies to the changes under review. For each relevant file, compute overlap against:
+
+- The changed AL object names and types — especially codeunits with `Subtype = Upgrade` or `Subtype = Install`, tables and tableextensions adding or changing fields, enums and enumextensions, and objects under `Hybrid*`/`Migration`/`Upgrade` namespaces.
+- The changed triggers and procedures, weighted toward `OnUpgradePerCompany`, `OnUpgradePerDatabase`, `OnInstallAppPerCompany`, and the `OnGetPerCompanyUpgradeTags`/`OnGetPerDatabaseUpgradeTags` subscribers.
+- Tokens extracted from the diff that relate to upgrade concerns (`Subtype = Upgrade`, `Upgrade Tag`, `HasUpgradeTag`, `SetUpgradeTag`, `DataTransfer`, `InitValue`, `ObsoleteState`, `ObsoleteReason`, `ObsoleteTag`, `DataVersion`, `ExecutionContext`, `value(`, `enum`, `enumextension`).
+
+A file enters the candidate worklist when its `keywords` intersect the extracted tokens or its topic matches a changed object type. When the diff contains no upgrade-related changes by any of the above signals, return `outcome: "not-applicable"` without evaluating files.
+
+Once the candidate worklist is known, resolve layer-precedence conflicts per READ. Drop lower-precedence files whose normative guidance directly contradicts a higher-precedence candidate, and record each dropped file in `suppressed` with `reason: "layer-precedence"`. Files suppressed by configuration are recorded with `reason: "configuration"`.
+
+When the post-conflict worklist is empty because no applicable upgrade knowledge exists, or because configuration suppressed every candidate, emit `outcome: "no-knowledge"`. When the worklist is empty because no applicable upgrade knowledge matched the changes, emit `outcome: "completed"` with an empty `findings` array.
+
+## Action
+
+For each worklist entry, evaluate the diff against the file's `## Best Practice` and `## Anti Pattern` sections. Emit findings as follows:
+
+- When the diff contains a clear match for an Anti Pattern, emit a finding with severity `major` or `blocker`, a message summarizing the anti-pattern, `location` pointing to the offending line or range, and a `references` entry pointing to the knowledge file. Use `blocker` for irreversible data corruption (enum-ordinal shift, unguarded reads that abort the upgrade) and for changes that would ship to customers without a migration path (new InitValue on an existing table without upgrade code).
+- When the diff contains code that contradicts a Best Practice without being a full anti-pattern, emit `minor` with the same reference shape.
+- When the skill cannot detect a violation but the file is clearly applicable to the change, emit `info` citing the file.
+
+Set `confidence` to:
+
+- `high` when the detection is based on an unambiguous pattern match.
+- `medium` when detection relies on heuristics or when any frontmatter dimension was `unknown`.
+- `low` when the finding is an advisory derived only from applicability.
+
+Outcome selection:
+
+- `completed` — the skill evaluated every worklist item.
+- `no-knowledge` — no applicable upgrade knowledge survived filtering.
+- `not-applicable` — the diff touches no upgrade, install, schema, or enum surface.
+- `partial` — a budget was hit before the worklist was exhausted.
+- `failed` — an unrecoverable error occurred.
+
+## Output
+
+Output conforms to the DO output contract. A populated example:
+
+```json
+{
+  "skill": { "id": "al-upgrade-review", "version": 1 },
+  "outcome": "completed",
+  "summary": {
+    "counts": { "blocker": 1, "major": 0, "minor": 0, "info": 0 },
+    "coverage": { "worklist-size": 1, "items-evaluated": 1 }
+  },
+  "findings": [
+    {
+      "id": "microsoft/knowledge/upgrade/enum-changes-must-be-additive-at-the-end.md",
+      "severity": "blocker",
+      "message": "A new enum value was inserted at ordinal 1, shifting every subsequent value by one. Rows that store the old ordinal 1 will silently resolve to the new value. Per the referenced guidance, enum values must be appended at the end.",
+      "location": {
+        "file": "src/Shared/OrderStatus.Enum.al",
+        "line": 7
+      },
+      "references": [
+        { "path": "microsoft/knowledge/upgrade/enum-changes-must-be-additive-at-the-end.md" }
+      ],
+      "confidence": "high"
+    }
+  ],
+  "suppressed": []
+}
+```