docs(sf): wire parentTrace into advisory-partner dispatch

Adds a Dispatch Pattern subsection showing the parentTrace shape for
advisory review. For advisory, the trace is the planner's reasoning trail
(alternatives considered, untested assumptions, explicit out-of-scope) —
not tool calls. This lets the advisory reviewer catch the gap between
what the planner thought and what the artefact says, which is exactly
what advisory review exists to catch.

src/resources/extensions/sf/skills/advisory-partner/SKILL.md

@@ -24,6 +24,34 @@ Use `subagent` to dispatch an advisory review (with the `validation` model) when
 - A significant architectural decision needs challenge — dispatch advisory, then write the ADR
 - The planning model is uncertain and needs a second opinion
 
+### Dispatch Pattern
+
+Pass `parentTrace` so the advisory agent reviews the planner's actual
+reasoning trail — not just the artefact that landed. For advisory dispatch,
+the trace shape is *reasoning*, not *tool calls*: alternatives considered,
+assumptions made, what the planner is uncertain about, what was rejected
+and why. The advisory agent uses this to find the gap between what the
+planner *thought* and what the artefact *says*.
+
+```
+subagent({
+  agent: "reviewer",
+  model: "<validation-tier model>",
+  parentTrace: "Reasoning trail (what the planner considered):\n" +
+               "- Alternatives weighed: A vs B vs C; chose B because <reason>\n" +
+               "- Untested assumptions: <assumption 1>, <assumption 2>\n" +
+               "- Where the planner is uncertain: <one or two specifics>\n" +
+               "- What was explicitly out of scope: <items>",
+  task: "Apply the advisory-partner protocol to <artefact path>. " +
+        "Answer Q1-Q5, run the trap scan, end with ADVISORY VERDICT."
+})
+```
+
+The advisory verdict carries more weight when the reviewer can see *what
+the planner thought* and not just *what the planner wrote*. Hidden
+assumptions and waved-away objections are exactly what advisory review
+exists to catch.
+
 ---
 
 ## Advisory Review Protocol