fix: resilient fallback for every plugin RPC (reddit/devvit#258 work-around)

.env.example

@@ -8,3 +8,25 @@ OPENAI_API_KEY=sk-...
 
 # Optional: override the model the smoke test uses (default: gpt-5.4-nano).
 # OPENAI_MODEL=gpt-5.4-mini
+
+# ─── LOCAL-ONLY PLAYTEST ESCAPE HATCHES ────────────────────────────────────
+# These flags are read by `vite build` for `npx devvit playtest` ONLY. The
+# deployed Reddit runtime does not set them — production behaviour is to
+# read every value from Devvit settings via `settings.get(...)`.
+
+# When the Devvit `settings` plugin RPC is unreachable inside the runtime
+# (we saw this on r/SocialSeeding 2026-05-13), set this to a falsy 'mock' to
+# bypass settings.get + fetch entirely in callOpenAI and return a fixed,
+# deterministic fake compiled rule. Useful for testing the compose-rule
+# UI flow when the platform is misbehaving. Unset / any other value =
+# normal OpenAI call path.
+# VIBE_MOD_AI_PROVIDER=mock
+
+# When the Devvit `settings` plugin RPC is unreachable AND you want to
+# run the *real* OpenAI call locally, set this to '1' and put your key in
+# OPENAI_API_KEY above. callOpenAI will fall back to that env value ONLY
+# if both `settings.get(subredditOpenaiApiKey)` and `settings.get(openaiApiKey)`
+# failed to return a key. Do NOT ship a built bundle with this enabled to
+# the public app directory — the env var is meant to be set on the local
+# machine running playtest only.
+# VIBE_MOD_LOCAL_OPENAI_FALLBACK=1

eslint.config.js

@@ -1,4 +1,4 @@
-// eslint.config.js — flat config (ESLint 9). See https://eslint.org/docs/latest/use/configure/configuration-files
+// eslint.config.js — flat config (ESLint 10). See https://eslint.org/docs/latest/use/configure/configuration-files
 // Pairs with Prettier: this file owns *correctness* rules; Prettier owns formatting
 // (eslint-config-prettier, applied last, disables any formatting rules that would conflict).
 
@@ -27,6 +27,19 @@ export default tseslint.config(
       eqeqeq: ['error', 'smart'],
       'no-var': 'error',
       'prefer-const': 'error',
+      // ESLint 10 introduced `no-useless-assignment`, which fires on the
+      // common resilient-fallback pattern:
+      //
+      //   let bundle: T | null = null;       // <- flagged as useless
+      //   try { bundle = await fetchIt(); }
+      //   catch (err) { /* fall back */ }
+      //   if (!bundle) return ...;            // <- but the default IS used
+      //
+      // The default value IS read on the catch path; the rule's analysis
+      // doesn't see through the try/catch. Disable so we can keep the
+      // pattern (used heavily for reddit/devvit#258 workaround — every
+      // plugin RPC call is wrapped this way). See PR #30.
+      'no-useless-assignment': 'off',
     },
   },
   {