Tighten precision bar for agent findings and cap their severity

Agent findings (model-judgment findings not backed by a curated knowledge
file) were producing too many false positives. Raise their emission bar and
make them advisory:

- skills/do.md: add a canonical 'Precision bar' for agent findings (emit only
  concrete, material defects an expert would agree on; steelman first; an
  explicit never-emit list; 'when in doubt, omit') and cap agent-finding
  severity at minor (advisory, non-gating), with a promotion note for
  severe-but-uncovered concerns.
- al-code-review.md: decouple the mandatory self-review reasoning from output
  so emitting zero agent findings is a valid outcome; add the severity cap.
- Six leaf review skills: add the per-domain precision bar and severity cap
  (style leaf gets domain-appropriate wording).

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

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

@@ -61,7 +61,7 @@ Set `confidence` to:
 - `medium` when detection relies on heuristics or when any frontmatter dimension was `unknown`.
 - `low` when the finding is an advisory derived only from applicability.
 
-After evaluating each worklist entry, also consider whether the diff exhibits a privacy defect the agent recognises from its general AL knowledge that no knowledge file in the worklist covers. Such candidates are agent findings within this skill's domain — emit them with `references: []`, an `id` slug prefixed with `agent:`, `confidence` capped at `medium`, and a `message` that is self-contained (describing both the issue and a concrete recommendation, since there is no knowledge-file footer for the consumer to fall back on). The scope is strictly privacy; defects outside this domain belong to other leaves and MUST NOT be emitted here. Before emitting, check the worklist for a knowledge file that matches the candidate — if one exists, upgrade the candidate to a knowledge-backed finding instead. See `skills/do.md` for the full contract.
+After evaluating each worklist entry, also consider whether the diff exhibits a privacy defect the agent recognises from its general AL knowledge that no knowledge file in the worklist covers. Such candidates are agent findings within this skill's domain — emit them with `references: []`, an `id` slug prefixed with `agent:`, `confidence` capped at `medium`, `severity` capped at `minor` (agent findings are advisory and non-gating), and a `message` that is self-contained (describing both the issue and a concrete recommendation, since there is no knowledge-file footer for the consumer to fall back on). Hold every candidate to the precision bar in `skills/do.md` (*Agent findings*): emit only a concrete, material privacy defect a knowledgeable BC reviewer would agree is wrong — steelman it first and drop anything stylistic, speculative, dependent on code outside the diff, or merely a valid alternative; when in doubt, omit. The scope is strictly privacy; defects outside this domain belong to other leaves and MUST NOT be emitted here. Before emitting, check the worklist for a knowledge file that matches the candidate — if one exists, upgrade the candidate to a knowledge-backed finding instead. See `skills/do.md` for the full contract.
 
 For every emitted finding, decide whether the fix is mechanical. A fix is mechanical when it is small, local, and unambiguous from the diff context (for example: delete unreachable lines; replace `Count() > 0` with `not IsEmpty()`; move a local `Label` to object scope; add a missing `ToolTip`, `OptionCaption`, or `DataClassification`; replace a string-concatenated `Error` with a Label-backed call; change an over-broad permission token; or add an obvious `else`/guard branch). For mechanical findings, emit `findings[].suggested-code` with the literal replacement for the source lines indicated by `location`. The payload must be a verbatim replacement — no diff markers, no fences, no commentary — that the consumer can render as a one-click suggestion. When a `.good.al` companion exists and the diff context matches the `.bad.al` shape, adapt the `.good.al` replacement into `suggested-code`.