feat: single-source cross-app wire contracts in @boocode/contracts (v2.7.13)

Move all hand-synced cross-app wire contracts into one built workspace
package, @boocode/contracts, consumed by server/web/coder/coder-web via
workspace:* + a per-subpath exports map. The ws-frames and provider-config
Zod schemas are schema-first (z.infer); MessageMetadata, ErrorReason,
AgentSessionConfig, the provider snapshot types, and WorktreeRiskReport are
each single-sourced. Deletes the byte-identical copies and their parity
tests, fixes a live AgentSessionConfig drift (coder dead copy removed,
unified to the web required/nullable shape), removes the dead pending_change
WS arms in the fallback SPA, and inverts the build order (contracts builds
first) across root build, Dockerfile, and the coder deploy docs. Reverses
the shared-package decision declined in v2.5.12.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

apps/coder/src/services/worktrees.ts

@@ -8,6 +8,7 @@
  */
 import type { Sql } from '../db.js';
 import { hostExec } from './host-exec.js';
+import type { WorktreeRiskReport } from '@boocode/contracts/worktree-risk';
 
 export const WORKTREE_BASE = '/tmp/booworktrees';
 
@@ -379,22 +380,8 @@ export async function rebaselineWorktreeAfterApply(
 }
 
 // ─── Session-delete work-loss guard ─────────────────────────────────────────
-
-/**
- * Risk report for a single worktree, returned by checkWorktreeWorkAtRisk.
- * `atRisk` is the gate the server reads before allowing a session delete.
- * A git error never silently passes — it forces `atRisk` true and surfaces
- * the message in `error` (fail-closed).
- */
-export interface RiskReport {
-  worktreePath: string;
-  branch: string;
-  dirty: boolean;   // uncommitted working-tree changes (incl. untracked)
-  unpushed: number; // commits ahead of upstream, or -1 if no upstream is set
-  unmerged: number; // commits on this branch not in the project default branch
-  atRisk: boolean;  // dirty || unmerged > 0 || (upstream && unpushed > 0) || git error
-  error?: string;   // populated on a git failure; presence forces atRisk
-}
+// WorktreeRiskReport single-sourced in @boocode/contracts — edit the package, not here.
+export type { WorktreeRiskReport };
 
 /**
  * Resolve the project's default branch as a git-usable ref (e.g. "origin/main").
@@ -448,7 +435,7 @@ async function detectDefaultBranchRef(
 export async function checkWorktreeWorkAtRisk(
   worktreePath: string,
   opts?: { signal?: AbortSignal },
-): Promise<RiskReport> {
+): Promise<WorktreeRiskReport> {
   // Branch name — also doubles as the "is this still a git worktree?" probe.
   const br = await hostExec(
     `git -C ${shellEscape(worktreePath)} rev-parse --abbrev-ref HEAD`,