diff --git a/.markdownlint.jsonc b/.markdownlint.jsonc
index 190881a..70e86d6 100644
--- a/.markdownlint.jsonc
+++ b/.markdownlint.jsonc
@@ -9,14 +9,11 @@
   "MD026": false, // trailing punctuation in headings
   "MD036": false, // emphasis used as heading — used intentionally in callouts
   "MD024": { "siblings_only": true }, // repeated headings ok if under different parents
-  "MD029": { "style": "ordered" },
+  "MD029": { "style": "ordered" }
 
-  // --- Relaxed while legacy briefs are being rewritten in the enrichment pass ---
-  // These will be re-tightened in the final polish PR once every file has been
-  // regenerated with clean spacing. Tracked in the CHANGELOG / final-polish task.
-  "MD022": false, // blanks around headings
-  "MD032": false, // blanks around lists
-  "MD040": false, // fenced code language
-  "MD047": false, // single trailing newline
-  "MD009": false  // trailing spaces
+  // Structural rules (MD022 blanks-around-headings, MD032 blanks-around-lists,
+  // MD040 fenced-code-language, MD047 single-trailing-newline, MD009
+  // no-trailing-spaces) are now ENFORCED again: every brief has been rewritten
+  // with clean spacing, so the temporary relaxation from the enrichment pass is
+  // no longer needed.
 }
diff --git a/CHANGELOG.md b/CHANGELOG.md
index e9769f5..b22ea07 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,6 +2,31 @@
 
 All notable changes to this project will be documented in this file.
 
+## [4.0.0] - 2026-07-25
+
+### Major Changes
+
+- **Every project is now a rich guided exercise**: all 180 project briefs were rewritten from short stubs into a consistent template — Overview, Prerequisites, Learning Objectives, Functional Requirements (or Requirements & Constraints for System Design), Suggested Milestones (or Suggested Approach), Data & Interface Sketch (or Architecture Sketch), Stretch Goals, Definition of Done (or Deliverables), Common Pitfalls, and curated Resources. Briefs describe *what* to build and *why*, with illustrative sketches only — never full solution code.
+- **Fully bilingual**: every brief, track landing page, and top-level document now ships in English (`README.md`) and Brazilian Portuguese (`README.pt-BR.md`), with a language switcher at the top of each.
+
+### Added
+
+- **360 project brief files**: 180 enriched English `README.md` + 180 new `README.pt-BR.md`.
+- **Bilingual docs**: `README.pt-BR.md` (root) and `CONTRIBUTING.pt-BR.md`.
+- **Reusable templates**: `.github/PROJECT_TEMPLATE.md` and `.github/PROJECT_TEMPLATE.pt-BR.md`.
+- **Community health files**: bilingual `CODE_OF_CONDUCT.md` and `SECURITY.md`.
+- **GitHub tooling**: issue forms (new project idea, content issue, enhancement) + config, `PULL_REQUEST_TEMPLATE.md`, and `CODEOWNERS`.
+- **Continuous integration**: `markdown-lint` and offline `link-check` GitHub Actions workflows.
+
+### Fixed
+
+- **76 broken navigation links** across the six track READMEs (link targets now point to the real project folders).
+
+### Changed
+
+- **Root README and 6 track landing pages** rewritten with badges, tables of contents, clearer learning paths, and language switchers.
+- **CONTRIBUTING** aligned with the actual repository structure and the new rich template.
+
 ## [3.0.0] - 2026-04-05
 
 ### Major Changes
@@ -21,7 +46,7 @@ All notable changes to this project will be documented in this file.
 ### Added
 
 - **Main Banner Image**: `projects/images/banner-main.png`
-- **Domain Banners**: 
+- **Domain Banners**:
   - `projects/images/banner-backend.png`
   - `projects/images/banner-frontend.png`
   - `projects/images/banner-data-science.png`
@@ -46,7 +71,7 @@ All notable changes to this project will be documented in this file.
 
 ### New Repository Structure
 
-```
+```text
 projects-library/
 ├── projects/
 │   ├── backend/
@@ -84,11 +109,13 @@ projects-library/
 ### Renamed
 
 **Main Folders:**
+
 - `iniciante/` → `beginner/`
 - `intermediario/` → `intermediate/`
 - `avancado/` → `advanced/`
 
 **Beginner Projects:**
+
 - `gerador-de-senha/` → `password-generator/`
 - `lista-de-tarefas/` → `todo-list/`
 - `calculadora-simples/` → `simple-calculator/`
@@ -106,6 +133,7 @@ projects-library/
 - `checklist-compras/` → `shopping-checklist/`
 
 **Intermediate Projects:**
+
 - `notas-markdown/` → `markdown-notes/`
 - `encurtador-url/` → `url-shortener/`
 - `dashboard-gastos/` → `expenses-dashboard/`
@@ -118,6 +146,7 @@ projects-library/
 - `gerador-relatorios-pdf/` → `pdf-report-generator/`
 
 **Advanced Projects:**
+
 - `ecommerce-completo/` → `ecommerce-platform/`
 - `rede-social/` → `social-network/`
 - `gestao-financeira/` → `financial-management/`
@@ -132,6 +161,7 @@ projects-library/
 ### Project Structure
 
 Each project now contains:
+
 - **Description**: Clear, concise project overview
 - **Features**: Core functionality requirements
 - **Learning Objectives**: Key concepts and skills to develop
@@ -150,4 +180,4 @@ This repository serves as a curated collection of project ideas for developers a
 - Initial repository with 35 projects in Portuguese
 - Multi-language implementations planned (JavaScript, Python, Clojure)
 - Emoji-rich documentation
-- Technology-specific suggestion
\ No newline at end of file
+- Technology-specific suggestion