chore(lint): one shared project service; ignore harness-local .claude state

Two independent multipliers were pushing bare `pnpm run lint` past node's
default heap:

1. parserOptions.project expanded to every package tsconfig plus the root
   one — each matched config built its OWN ts.Program, and the dev paths
   map pulls sibling package SOURCES (plus the vendored Cordis stack) into
   every such program, so resident memory grew as sum-of-closures, not
   repo size: ~4.6 GB peak for 425 repo files. projectService shares one
   tsserver-style graph: ~2.0 GB peak, ~28 s → ~14 s wall.

2. `eslint .` traversed .claude/ harness-local state — stale worktree
   checkouts there carry tens of thousands of additional .ts files
   (whole-repo copies), roughly tripling the work again even under the
   project service. Other checkouts are not this one's sources; ignore
   them like node_modules. (#169 carries the identical ignore line inside
   its chain; the hunks dedupe on its next rebase.)

Type-aware rules verified live under the service: a floating-promise
probe still trips no-floating-promises.

eslint.config.mjs

@@ -22,6 +22,7 @@ export default tseslint.config(
       '**/lib/**',
       '**/node_modules/**',
       '**/.sessions/**',
+      '.claude/**', // harness-local state (worktrees, skills) — other checkouts, not this one's sources
       '**/.doc-typecheck-*/**',
       'vendor/**', // vendored source keeps upstream style and idioms
       '**/*.js',
@@ -38,7 +39,14 @@ export default tseslint.config(
     ],
     languageOptions: {
       parserOptions: {
-        project: ['./packages/*/*/tsconfig.json', './tsconfig.json'],
+        // One shared tsserver-style project service instead of 60+ standalone
+        // per-package programs: the old `project` glob built every package's
+        // full dependency closure (sibling sources via the dev `paths` map +
+        // the vendored Cordis stack) as its own program and kept them all
+        // resident — ~5 GB peak, an OOM past node's default heap. The service
+        // resolves each file to its nearest owning tsconfig and shares the
+        // graph.
+        projectService: true,
         tsconfigRootDir: import.meta.dirname,
       },
     },
@@ -89,7 +97,9 @@ export default tseslint.config(
     ],
     languageOptions: {
       parserOptions: {
-        project: ['./tsconfig.json'],
+        // Same shared project service as the src block: test files resolve
+        // through the root tsconfig (its include covers every tests/ tree).
+        projectService: true,
         tsconfigRootDir: import.meta.dirname,
       },
     },