diff --git a/.gitignore b/.gitignore
index 97c9f8096..9a5f28709 100644
--- a/.gitignore
+++ b/.gitignore
@@ -186,6 +186,7 @@ build/
 /gsd-core/bin/lib/workstream.cjs
 /gsd-core/bin/lib/roadmap.cjs
 /gsd-core/bin/lib/audit.cjs
+/gsd-core/bin/lib/git-base-branch.cjs
 __pycache__/
 *.pyc
 .venv/
diff --git a/gsd-core/bin/lib/git-base-branch.cjs b/gsd-core/bin/lib/git-base-branch.cjs
deleted file mode 100644
index b30cfda93..000000000
--- a/gsd-core/bin/lib/git-base-branch.cjs
+++ /dev/null
@@ -1,220 +0,0 @@
-"use strict";
-/**
- * Git Base-Branch Resolver — issue #1146.
- *
- * Single source of truth for detecting the repository's default branch.
- * Replaces the duplicated per-workflow bash detection that only consulted
- * `refs/remotes/origin/HEAD` then hardcoded `:-main`, which silently
- * returned "main" for repos whose default branch is "master" whenever
- * origin/HEAD was unset (git init + remote add / fetch without set-head /
- * most CI checkouts / many worktrees).
- *
- * Precedence ladder (highest to lowest):
- *   1. `git.base_branch` config override from .planning/config.json
- *   2. `git symbolic-ref --short refs/remotes/origin/HEAD`  (fast, no network)
- *   3. `git remote show origin` HEAD branch  ← AUTHORITATIVE; works when #2 unset
- *   4. Local branch existence: "master" present + "main" absent → "master";
- *      "main" present → "main"
- *   5. "main"  (last-resort default)
- *
- * Every git subprocess is bounded with a timeout (≤ 30 s); on timeout/error
- * the resolver degrades gracefully to the next tier — it never throws.
- *
- * Pure/testable: all I/O is injectable via the `deps` argument so unit
- * tests can run without touching the real filesystem or spawning real git.
- */
-var __importDefault = (this && this.__importDefault) || function (mod) {
-    return (mod && mod.__esModule) ? mod : { "default": mod };
-};
-Object.defineProperty(exports, "__esModule", { value: true });
-exports.readConfigBaseBranch = readConfigBaseBranch;
-exports.trySymbolicRef = trySymbolicRef;
-exports.tryRemoteShow = tryRemoteShow;
-exports.tryLocalBranch = tryLocalBranch;
-exports.resolveBaseBranch = resolveBaseBranch;
-exports.gitWorktreeInfoInternal = gitWorktreeInfoInternal;
-exports.cmdGitBaseBranch = cmdGitBaseBranch;
-const node_fs_1 = __importDefault(require("node:fs"));
-const node_path_1 = __importDefault(require("node:path"));
-const shell_command_projection_cjs_1 = require("./shell-command-projection.cjs");
-// ─── Helpers ──────────────────────────────────────────────────────────────────
-/**
- * Safely look up `git.base_branch` from the project's config.json.
- * Returns the configured value (a non-empty, non-null string) or null.
- */
-function readConfigBaseBranch(planningDir, deps) {
-    const readFile = deps?.readFile ??
-        ((p) => { try {
-            return node_fs_1.default.readFileSync(p, 'utf8');
-        }
-        catch {
-            return null;
-        } });
-    const configPath = node_path_1.default.join(planningDir, 'config.json');
-    const raw = readFile(configPath);
-    if (!raw)
-        return null;
-    let cfg;
-    try {
-        cfg = JSON.parse(raw);
-    }
-    catch {
-        return null;
-    }
-    if (!cfg || typeof cfg !== 'object' || Array.isArray(cfg))
-        return null;
-    const top = cfg;
-    // Support both "git.base_branch" (nested) and "base_branch" (flat legacy)
-    const gitSection = top.git;
-    if (gitSection && typeof gitSection === 'object' && !Array.isArray(gitSection)) {
-        const nested = gitSection.base_branch;
-        if (typeof nested === 'string' && nested.trim())
-            return nested.trim();
-    }
-    const flat = top.base_branch;
-    if (typeof flat === 'string' && flat.trim())
-        return flat.trim();
-    return null;
-}
-/**
- * Try `git symbolic-ref --short refs/remotes/origin/HEAD` (no network).
- * Strips the `origin/` prefix to return just the branch name.
- * Returns null if unset or on error/timeout.
- */
-function trySymbolicRef(cwd, execGit) {
-    try {
-        const r = execGit(['symbolic-ref', '--quiet', '--short', 'refs/remotes/origin/HEAD'], { cwd, timeout: 5_000 });
-        if (r.exitCode !== 0 || !r.stdout)
-            return null;
-        // Output is e.g. "origin/main" — strip the prefix
-        const branch = r.stdout.trim().replace(/^origin\//, '');
-        return branch || null;
-    }
-    catch {
-        return null;
-    }
-}
-/**
- * Try `git remote show origin` to read the HEAD branch.
- * This is authoritative when origin/HEAD is unset locally.
- * Requires network access but succeeds in the common CI case where
- * origin/HEAD was never set after `git init && git remote add origin`.
- *
- * Parses the line:  `HEAD branch: <name>`
- * Returns null on error, timeout, or if the output is malformed.
- */
-function tryRemoteShow(cwd, execGit) {
-    try {
-        const r = execGit(['remote', 'show', 'origin'], { cwd, timeout: 15_000 });
-        if (r.exitCode !== 0 || !r.stdout)
-            return null;
-        // The line looks like: "  HEAD branch: master"
-        const m = r.stdout.match(/^\s*HEAD branch:\s*(\S+)\s*$/m);
-        if (!m)
-            return null;
-        const branch = m[1];
-        // git emits "(unknown)" when the remote is offline but the local cache
-        // resolved it; treat that as non-authoritative and fall through.
-        if (!branch || branch === '(unknown)')
-            return null;
-        return branch;
-    }
-    catch {
-        return null;
-    }
-}
-/**
- * Detect local branch existence as a tie-breaker when no remote info is available.
- *
- * Rules:
- *   - "master" present AND "main" absent → "master"
- *   - "main" present → "main"
- *   - Neither → null (fall through to default)
- *
- * Returns null on error/timeout.
- */
-function tryLocalBranch(cwd, execGit) {
-    try {
-        const r = execGit(['branch', '--list', 'main', 'master'], { cwd, timeout: 5_000 });
-        if (r.exitCode !== 0 || !r.stdout)
-            return null;
-        // `git branch --list main master` outputs one line per matching branch
-        const lines = r.stdout.split('\n').map(l => l.trim().replace(/^\*\s*/, ''));
-        const hasMain = lines.includes('main');
-        const hasMaster = lines.includes('master');
-        if (hasMaster && !hasMain)
-            return 'master';
-        if (hasMain)
-            return 'main';
-        return null;
-    }
-    catch {
-        return null;
-    }
-}
-/**
- * Resolve the default/base branch for the repository at `cwd`.
- *
- * Consults the full precedence ladder and always returns a non-empty string.
- * Never throws.
- */
-function resolveBaseBranch(cwd, deps) {
-    const execGit = deps?.execGit ?? shell_command_projection_cjs_1.execGit;
-    // Derive .planning dir relative to cwd (mirrors planningDir() in core.cjs)
-    const planningDir = node_path_1.default.join(cwd, '.planning');
-    // 1. Config override
-    const configured = readConfigBaseBranch(planningDir, deps);
-    if (configured)
-        return configured;
-    // 2. symbolic-ref (fast, no network)
-    const symref = trySymbolicRef(cwd, execGit);
-    if (symref)
-        return symref;
-    // 3. git remote show origin (authoritative when origin/HEAD unset)
-    const remoteShow = tryRemoteShow(cwd, execGit);
-    if (remoteShow)
-        return remoteShow;
-    // 4. Local branch existence
-    const local = tryLocalBranch(cwd, execGit);
-    if (local)
-        return local;
-    // 5. Last-resort default
-    return 'main';
-}
-/**
- * Detect whether `cwd` sits inside a git worktree, and if so, return the
- * absolute path of the worktree root.
- */
-function gitWorktreeInfoInternal(cwd) {
-    try {
-        const insideResult = (0, shell_command_projection_cjs_1.execGit)(['rev-parse', '--is-inside-work-tree'], { cwd, timeout: 5000 });
-        if (insideResult.exitCode !== 0) {
-            return { inside: false, worktreeRoot: null };
-        }
-        const insideStdout = String(insideResult.stdout || '').trim();
-        if (insideStdout !== 'true') {
-            return { inside: false, worktreeRoot: null };
-        }
-        const rootResult = (0, shell_command_projection_cjs_1.execGit)(['rev-parse', '--show-toplevel'], { cwd, timeout: 5000 });
-        if (rootResult.exitCode !== 0) {
-            return { inside: true, worktreeRoot: null };
-        }
-        const root = String(rootResult.stdout || '').trim();
-        return { inside: true, worktreeRoot: root || null };
-    }
-    catch {
-        return { inside: false, worktreeRoot: null };
-    }
-}
-// ─── CLI entry point ──────────────────────────────────────────────────────────
-/**
- * CLI command: `gsd-tools git base-branch`
- * Resolves the default branch and writes it to stdout (raw string, newline-terminated).
- * Called by workflows via `gsd_run query git.base-branch`.
- */
-function cmdGitBaseBranch(cwd, _args, deps) {
-    const branch = resolveBaseBranch(cwd, deps);
-    const write = deps?.write ?? ((s) => process.stdout.write(s));
-    write(branch + '\n');
-    return branch;
-}