Cut review-cost drivers: turn-aware models, inline diffs, scoped evidence

Round-2 fractals eval regressed to 70min/32.2M tokens (vs round-1's
42.8min/14.5M) while reaching baseline-parity quality. Per-subagent turn
profiling attributed it to: haiku dispatches taking 2-3x the turns of
sonnet (678 of 1197 subagent turns), reviewers re-fetching diffs by hand
(518 Bash calls), and evidence-rule narration. Changes: turn-count-beats-
token-price model guidance; controllers paste small diffs into reviewer
prompts (reviewers then need few or no tool calls); evidence scoped to
findings and would-be-bare-yes checks; Important defined as cannot-trust-
until-fixed with coverage suggestions Minor; fixes dispatched only for
Critical/Important.

skills/subagent-driven-development/SKILL.md

@@ -104,6 +104,12 @@ most capable model; a subtle concurrency change does.
 omitted model inherits your session's model — often the most capable and
 most expensive — which silently defeats this section.
 
+**Turn count beats token price.** Wall-clock and context cost scale with how
+many turns a subagent takes, and the cheapest models routinely take 2-3× the
+turns on multi-step work — costing more overall. Use a mid-tier model as the
+floor for implementers and reviewers; reserve the cheapest tier for
+single-file mechanical fixes.
+
 **Task complexity signals (implementation tasks):**
 - Touches 1-2 files with a complete spec → cheap model
 - Touches multiple files with integration concerns → standard model
@@ -154,6 +160,11 @@ final whole-branch review. When you fill a reviewer template:
 - Include the spec/design's global constraints that bind the task (version
   floors, naming and copy rules, platform requirements) in the requirements
   you paste — a reviewer can only enforce what you hand them.
+- Paste the task's diff (`git diff BASE..HEAD` output) into the reviewer
+  prompt when it fits comfortably (up to a few hundred lines). A reviewer
+  with the diff in hand needs few or no tool calls.
+- Dispatch fix subagents for Critical and Important findings. Record Minor
+  findings and move on — they roll up to the final whole-branch review.
 
 ## Prompt Templates
 

skills/subagent-driven-development/code-quality-reviewer-prompt.md

@@ -32,6 +32,14 @@ Subagent (general-purpose):
     git diff [BASE_SHA]..[HEAD_SHA]
     ```
 
+    ## Diff
+
+    [DIFF]
+
+    If the diff is provided above, review from it directly — do not re-run
+    the git commands or re-read the files it already shows. Fetch anything
+    further only for a named concrete risk.
+
     ## Read-Only Review
 
     Your review is read-only on this checkout. Do not mutate the working tree,
@@ -84,12 +92,15 @@ Subagent (general-purpose):
       significantly grow existing files? (Don't flag pre-existing file
       sizes — focus on what this change contributed.)
 
-    Answer each item above with file:line evidence, not a bare yes or no.
+    Cite file:line evidence for every finding and for any check you would
-    An unsupported "yes" is not a review.
+    otherwise answer with a bare "yes." Cite, don't narrate — a tight report
+    that points at lines beats a long one that retells the diff.
 
     ## Calibration
 
     Categorize issues by actual severity. Not everything is Critical.
+    Important means this task cannot be trusted until it is fixed;
+    "coverage could be broader" and polish suggestions are Minor.
     Acknowledge what was done well before listing issues — accurate praise
     helps the implementer trust the rest of the feedback.
 
@@ -127,5 +138,8 @@ Subagent (general-purpose):
 - `[TASK_TEXT]` — the task's requirements text or plan reference, for context
 - `[BASE_SHA]` — commit before this task
 - `[HEAD_SHA]` — current commit
+- `[DIFF]` — paste `git diff BASE..HEAD` output when it fits comfortably
+  (up to a few hundred lines); otherwise replace with "(not provided — run
+  the git commands above)"
 
 **Reviewer returns:** Strengths, Issues (Critical/Important/Minor), Task quality verdict

skills/subagent-driven-development/spec-reviewer-prompt.md

@@ -30,6 +30,13 @@ Subagent (general-purpose):
 
     Only read files in this diff. Do not crawl the broader codebase.
 
+    ## Diff
+
+    [DIFF]
+
+    If the diff is provided above, review from it directly — do not re-run
+    the git commands or re-read the files it already shows.
+
     Spec compliance is judged by reading the diff against the requirements.
     The implementer already ran the tests and reported TDD evidence — do not
     re-run them. If a requirement cannot be verified from this diff alone