fix(server): isolate paseo.json parse failures so they don't block fetch_workspaces

A malformed paseo.json (e.g. git-conflict markers) in any registered
workspace caused readPaseoConfig to throw, which propagated through
getScriptConfigs -> buildWorkspaceScriptPayloads ->
Session.describeWorkspaceRecord and failed the entire
fetch_workspaces_request with code=fetch_workspaces_failed. The client
showed no workspaces at all.

Reshape: separate loading (mechanism) from policy (per-caller).

- readPaseoConfig now returns a discriminated result
  ({ ok: true; config } | { ok: false; configPath; error }). Pure load,
  no logging, no opinions.
- Workspace projection owns its own policy via readPaseoConfigForProjection
  in script-status-projection.ts: warn via pino with configPath +
  workspaceDirectory + err, treat workspace as having no scripts, keep the
  list alive.
- spawnWorkspaceScript throws with cause so the existing
  handleStartWorkspaceScriptRequest catch logs it once with full context.
- The setup/teardown/terminal wrappers retain their pre-existing silent
  degradation on missing/broken config.
- getScriptConfigs takes a parsed PaseoConfig | null instead of repoRoot
  so the projection can pass the result through without double-reading.

Closes https://github.com/getpaseo/paseo/issues/598

packages/server/src/utils/worktree.ts

@@ -8,7 +8,7 @@ import { createHash } from "node:crypto";
 import * as pty from "node-pty";
 import stripAnsi from "strip-ansi";
 import { buildStringCommandShellInvocation } from "./string-command-shell.js";
-import { readPaseoConfigJson } from "./paseo-config-file.js";
+import { readPaseoConfigJson, resolvePaseoConfigPath } from "./paseo-config-file.js";
 export {
   PaseoConfigRawSchema,
   PaseoLifecycleCommandRawSchema,
@@ -197,31 +197,35 @@ export class UnknownBranchError extends Error {
   }
 }
 
-export function readPaseoConfig(repoRoot: string): PaseoConfig | null {
+export type ReadPaseoConfigResult =
+  | { ok: true; config: PaseoConfig | null }
+  | { ok: false; configPath: string; error: unknown };
+
+export function readPaseoConfig(repoRoot: string): ReadPaseoConfigResult {
   try {
     const json = readPaseoConfigJson(repoRoot);
     if (json === null) {
-      return null;
+      return { ok: true, config: null };
     }
-    return PaseoConfigSchema.parse(json);
-  } catch {
-    throw new Error(`Failed to parse paseo.json`);
+    return { ok: true, config: PaseoConfigSchema.parse(json) };
+  } catch (error) {
+    return { ok: false, configPath: resolvePaseoConfigPath(repoRoot), error };
   }
 }
 
 export function getWorktreeSetupCommands(repoRoot: string): string[] {
-  const config = readPaseoConfig(repoRoot);
-  return config?.worktree?.setup ?? [];
+  const result = readPaseoConfig(repoRoot);
+  return result.ok ? (result.config?.worktree?.setup ?? []) : [];
 }
 
 export function getWorktreeTeardownCommands(repoRoot: string): string[] {
-  const config = readPaseoConfig(repoRoot);
-  return config?.worktree?.teardown ?? [];
+  const result = readPaseoConfig(repoRoot);
+  return result.ok ? (result.config?.worktree?.teardown ?? []) : [];
 }
 
 export function getWorktreeTerminalSpecs(repoRoot: string): WorktreeTerminalConfig[] {
-  const config = readPaseoConfig(repoRoot);
-  const terminals = config?.worktree?.terminals;
+  const result = readPaseoConfig(repoRoot);
+  const terminals = result.ok ? result.config?.worktree?.terminals : undefined;
   if (!Array.isArray(terminals) || terminals.length === 0) {
     return [];
   }
@@ -254,8 +258,7 @@ export function getWorktreeTerminalSpecs(repoRoot: string): WorktreeTerminalConf
   return specs;
 }
 
-export function getScriptConfigs(repoRoot: string): Map<string, ScriptConfig> {
-  const config = readPaseoConfig(repoRoot);
+export function getScriptConfigs(config: PaseoConfig | null): Map<string, ScriptConfig> {
   const scripts = config?.scripts;
   if (!scripts || typeof scripts !== "object") {
     return new Map();