fix: restore DefaultDictionaryPredictor so custom words appear in suggestions

docs/agents/commands.md

@@ -37,11 +37,50 @@ Production builds write the unpacked extension output to `build/`.
 - Prefer `bun run bump` for version bumps. It runs `bun pm version`, which triggers the Bun `version` lifecycle and syncs the browser manifests through `scripts/update-manifest-version.cjs`.
 - Do not hand-edit manifest versions in `platform/*/manifest.json`.
 
+## Rebuilding Language Assets (presage data)
+
+The Presage prediction engine reads its configuration from `resources_js/<lang>/presage.xml` and loads language data from packed binary `.data` files in `public/third_party/libpresage/`. The `src/third_party/libpresage/libpresage.js` file embeds metadata (file offsets/sizes) that maps the virtual filesystem to those `.data` files.
+
+**Whenever you change a `presage.xml` file or `resources_js_lang_template/presage.xml`, you must repack:**
+
+```
+python3 scripts/rebuild_all.py --repack
+```
+
+This runs two steps:
+
+1. **Package** – repacks all `resources_js/` directories into updated `.data` files (copied to `public/third_party/libpresage/`) and regenerates the pre-JS loader stubs in `scripts/.deps/gen/`.
+2. **Link** – re-links `libpresage.js` with the new stubs embedded, requiring a pre-built `libpresage.so.1.1.1` in `scripts/.deps/presage/`.
+
+If the compiled `.so` is not present (i.e. `scripts/.deps/presage/` is missing), run a full rebuild first:
+
+```
+python3 scripts/rebuild_libpresage.py --deps --presage
+python3 scripts/rebuild_all.py --repack
+```
+
+After repacking, the following files will be modified and must be committed:
+
+- `public/third_party/libpresage/*.data`
+- `src/third_party/libpresage/libpresage.js`
+
+> **Note:** `resources_js/<lang>/presage.xml` files are generated from `resources_js_lang_template/presage.xml` during a full rebuild. Always edit the template first, then regenerate per-language files with a full rebuild or by manually applying the same change to all language variants.
+
 ## Release-Safe Defaults
 
 - If a change affects runtime behavior, run the expanded e2e suite described in [testing.md](testing.md).
 - If a change affects docs or workflows, keep [`README.md`](../../README.md) and [`CONTRIBUTING.md`](../../CONTRIBUTING.md) aligned with the same command surface.
 
+## Quality Gate (required before every PR)
+
+Run the full check suite and fix all errors before pushing:
+
+```
+bun run check
+```
+
+This runs lint (`eslint`), format check (`prettier --check`), and typecheck in sequence. All three must pass. Do not push a branch with a failing `bun run check`.
+
 ## PR Notes
 
 - Summarize the user-visible impact.

docs/agents/testing.md

@@ -10,6 +10,10 @@ Testing expectations depend on what changed. Use the smallest suite that still p
 - Dev-runtime e2e: `bun run test:e2e:dev`
 - Coverage matrix validation: `bun run check:e2e:coverage`
 
+## Regression Tests for Bug Fixes
+
+Every bug fix must include a regression test that would have caught the bug. Add the test to the most appropriate existing test file before writing the fix, or immediately after. The test must fail on the unfixed code and pass on the fixed code.
+
 ## Baseline Before a PR
 
 Run these for every PR:

eslint.config.js

@@ -21,6 +21,7 @@ export default defineConfig([
       "coverage/**",
       "node_modules/**",
       "public/third_party/**",
+      "scripts/.deps/**",
       "src/third_party/**",
     ],
   },