fix(ce-code-review): replace resolve-base.sh with prose-driven base detection

docs/skills/ce-code-review.md

@@ -116,7 +116,7 @@ Compound-engineering pipeline artifacts (`docs/brainstorms/*`, `docs/plans/*.md`
 
 You invoke `/ce-code-review` on a feature branch with a Rails auth change that includes a database migration.
 
-The skill detects you're on a feature branch (no PR yet), resolves the base via `scripts/resolve-base.sh`, and computes the diff. Stage 2 reads commit messages and writes a 2-3 line intent summary. Stage 2b auto-discovers the plan in `docs/plans/` from the branch name and reads its Requirements (R1-R8, U1-U6).
+The skill detects you're on a feature branch (no PR yet), resolves the base from `origin/HEAD` (or PR metadata when an open PR exists), and computes the diff. Stage 2 reads commit messages and writes a 2-3 line intent summary. Stage 2b auto-discovers the plan in `docs/plans/` from the branch name and reads its Requirements (R1-R8, U1-U6).
 
 Stage 3 selects reviewers: the 6 always-on, plus security (auth touched), reliability (background job for token cleanup), data migrations (migration file present), kieran-rails + dhh-rails (stack), schema-drift detector and deployment-verification agent (CE migration conditionals). Ten reviewers total, dispatched in parallel.
 
@@ -175,7 +175,7 @@ Concurrent use note: `mode:report-only` is the only mode safe to run alongside b
 
 | Argument | Effect |
 |----------|--------|
-| _(empty)_ | Reviews current branch (uses `scripts/resolve-base.sh` to detect base) |
+| _(empty)_ | Reviews current branch (detects base from `origin/HEAD` or PR metadata) |
 | `<PR number or URL>` | Reviews that PR (checks out, fetches metadata, reviews against PR base) |
 | `<branch name>` | Checks out and reviews against detected base |
 | `base:<sha-or-ref>` | Skips scope detection; reviews current checkout against that ref |

plugins/compound-engineering/skills/ce-code-review/SKILL.md

@@ -292,15 +292,13 @@ If the output is non-empty, inform the user: "You have uncommitted changes on th
 git checkout <branch>
 ```
 
-Then detect the review base branch and compute the merge-base. Run the `scripts/resolve-base.sh` script, which handles fork-safe remote resolution with multi-fallback detection (PR metadata -> `origin/HEAD` -> `gh repo view` -> common branch names):
+Then detect the review base branch and compute the merge-base.
 
-```
-RESOLVE_OUT=$(bash scripts/resolve-base.sh) || { echo "ERROR: resolve-base.sh failed"; exit 1; }
-if [ -z "$RESOLVE_OUT" ] || echo "$RESOLVE_OUT" | grep -q '^ERROR:'; then echo "${RESOLVE_OUT:-ERROR: resolve-base.sh produced no output}"; exit 1; fi
-BASE=$(echo "$RESOLVE_OUT" | sed 's/^BASE://')
-```
+**If a PR exists for `<branch>`** (check with `gh pr view <branch> --json baseRefName,url`): reuse PR mode's `PR_BASE_REMOTE` block above. Use `baseRefName` as `<base>` and derive `<base-repo>` from the PR URL (e.g., `EveryInc/foo` from `https://github.com/EveryInc/foo/pull/123`). The block already sets `$BASE` to the merge-base SHA — `origin` may point at the user's fork, which is why naive `origin/<base>` is unsafe and the fork-safe block is required.
+
+**If no PR exists**: derive the default branch. Primary source is `git symbolic-ref --quiet --short refs/remotes/origin/HEAD | sed 's#^origin/##'`; fall back to `gh repo view --json defaultBranchRef --jq '.defaultBranchRef.name'`, then to the first of `main`/`master`/`develop`/`trunk` that exists as `origin/<name>` or bare `<name>` locally. Compute `BASE=$(git merge-base HEAD <base-ref>)`, where `<base-ref>` is `origin/<base-branch>` when available, otherwise the bare local `<base-branch>` (covers single-branch clones, missing origin remote, and unfetched defaults). If `BASE` is empty and the clone is shallow (`git rev-parse --is-shallow-repository`), run `git fetch --unshallow origin` and retry.
 
-If the script outputs an error, stop instead of falling back to `git diff HEAD`; a branch review without the base branch would only show uncommitted changes and silently miss all committed work.
+If no base can be resolved, **stop**. Do not fall back to `git diff HEAD` — a branch review without the base would only show uncommitted changes and silently miss all committed work.
 
 On success, produce the diff:
 
@@ -312,15 +310,9 @@ You may still fetch additional PR metadata with `gh pr view` for title, body, li
 
 **If no argument (standalone on current branch):**
 
-Detect the review base branch and compute the merge-base using the same `scripts/resolve-base.sh` script as branch mode:
-
-```
-RESOLVE_OUT=$(bash scripts/resolve-base.sh) || { echo "ERROR: resolve-base.sh failed"; exit 1; }
-if [ -z "$RESOLVE_OUT" ] || echo "$RESOLVE_OUT" | grep -q '^ERROR:'; then echo "${RESOLVE_OUT:-ERROR: resolve-base.sh produced no output}"; exit 1; fi
-BASE=$(echo "$RESOLVE_OUT" | sed 's/^BASE://')
-```
+Apply the same base-detection logic as branch mode above, using the current branch (i.e., `gh pr view --json baseRefName,url` with no argument defaults to the current branch).
 
-If the script outputs an error, stop instead of falling back to `git diff HEAD`; a standalone review without the base branch would only show uncommitted changes and silently miss all committed work on the branch.
+If no base can be resolved, **stop**. Do not fall back to `git diff HEAD` — a standalone review without the base would only show uncommitted changes and silently miss all committed work on the branch.
 
 On success, produce the diff: