feat(cre): bootstrap Crystal project shell

- shard.yml with db, pg, sqlite3, tourmaline (deps), webmock (dev)
- Makefile with build/test/format/lint/demo targets
- .gitignore, .editorconfig, LICENSE (MIT), README skeleton
- ameba lint deferred until libpcre3-dev is available on this env

PROJECTS/intermediate/credential-rotation-enforcer/.editorconfig

@@ -0,0 +1,15 @@
+# ©AngelaMos | 2026
+# .editorconfig
+
+root = true
+
+[*]
+end_of_line = lf
+insert_final_newline = true
+charset = utf-8
+indent_style = space
+indent_size = 2
+trim_trailing_whitespace = true
+
+[*.md]
+trim_trailing_whitespace = false

PROJECTS/intermediate/credential-rotation-enforcer/.gitignore

@@ -0,0 +1,19 @@
+# ©AngelaMos | 2026
+# .gitignore
+
+/bin/
+/lib/
+/.shards/
+/.crystal/
+*.dwarf
+.env.local
+.env.pending
+*.pid
+/coverage/
+/tmp/
+*.log
+.DS_Store
+
+# Local-only dev docs (not committed to public repo)
+/docs/research/
+/docs/plans/

PROJECTS/intermediate/credential-rotation-enforcer/LICENSE

@@ -0,0 +1,21 @@
+MIT License
+
+Copyright (c) 2026 Carter Perez
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.

PROJECTS/intermediate/credential-rotation-enforcer/Makefile

@@ -0,0 +1,57 @@
+# ©AngelaMos | 2026
+# Makefile
+
+.PHONY: build build-dev test test-unit test-integration lint format format-check demo demo-full demo-full-down check ci clean
+
+CRYSTAL ?= crystal
+SHARDS ?= shards
+
+build:
+	$(SHARDS) build cre --release --no-debug
+
+build-dev:
+	$(SHARDS) build cre
+
+test:
+	$(CRYSTAL) spec --order=random
+
+test-unit:
+	$(CRYSTAL) spec spec/unit --order=random
+
+test-integration:
+	$(CRYSTAL) spec spec/integration --order=random
+
+lint:
+	@if [ -x ./bin/ameba ]; then \
+		./bin/ameba; \
+	else \
+		echo "ameba not installed (requires libpcre3-dev on Debian 13+); skipping lint"; \
+	fi
+
+format:
+	$(CRYSTAL) tool format
+
+format-check:
+	$(CRYSTAL) tool format --check
+
+demo:
+	$(SHARDS) build cre && ./bin/cre demo
+
+demo-full:
+	docker compose -f docker/docker-compose.yml up -d
+	@echo "Waiting for services..."
+	@sleep 8
+	$(SHARDS) build cre && ./bin/cre run --config=config/demo-full.cr
+
+demo-full-down:
+	docker compose -f docker/docker-compose.yml down -v
+
+check:
+	$(MAKE) format-check
+	$(MAKE) lint
+	$(MAKE) test
+
+ci: check
+
+clean:
+	rm -rf bin lib .shards .crystal coverage tmp

PROJECTS/intermediate/credential-rotation-enforcer/README.md

@@ -0,0 +1,13 @@
+<!--
+©AngelaMos | 2026
+README.md
+-->
+
+# Credential Rotation Enforcer (cre)
+
+A Crystal-based daemon that tracks and enforces credential rotation
+policies across AWS Secrets Manager, HashiCorp Vault, GitHub fine-grained
+PATs, and local `.env` files.
+
+> Full README, asciinema demos, and walkthrough live in `learn/`.
+> This README will be expanded in Phase 16 of the build.

PROJECTS/intermediate/credential-rotation-enforcer/shard.lock

@@ -0,0 +1,33 @@
+version: 2.0
+shards:
+  db:
+    git: https://github.com/crystal-lang/crystal-db.git
+    version: 0.11.0
+
+  html5:
+    git: https://github.com/naqvis/crystal-html5.git
+    version: 0.4.0
+
+  http_proxy:
+    git: https://github.com/mamantoha/http_proxy.git
+    version: 0.14.0+git.commit.5a02af05c5531c639efdf651431a86ec90905f71
+
+  pg:
+    git: https://github.com/will/crystal-pg.git
+    version: 0.26.0
+
+  sqlite3:
+    git: https://github.com/crystal-lang/crystal-sqlite3.git
+    version: 0.19.0
+
+  tourmaline:
+    git: https://github.com/protoncr/tourmaline.git
+    version: 0.28.0
+
+  webmock:
+    git: https://github.com/manastech/webmock.cr.git
+    version: 0.14.0
+
+  xpath2:
+    git: https://github.com/naqvis/crystal-xpath2.git
+    version: 0.2.0

PROJECTS/intermediate/credential-rotation-enforcer/shard.yml

@@ -0,0 +1,35 @@
+# ©AngelaMos | 2026
+# shard.yml
+
+name: cre
+version: 0.1.0
+description: |
+  Credential Rotation Enforcer - tracks and enforces credential rotation
+  policies across cloud secret managers, vaults, and developer tooling.
+authors:
+  - Carter Perez <carterperez2222@gmail.com>
+license: MIT
+crystal: ">= 1.20.0"
+
+targets:
+  cre:
+    main: src/cre.cr
+
+dependencies:
+  db:
+    github: crystal-lang/crystal-db
+    version: ~> 0.9
+  pg:
+    github: will/crystal-pg
+    version: ~> 0.9
+  sqlite3:
+    github: crystal-lang/crystal-sqlite3
+    version: ~> 0.9
+  tourmaline:
+    github: protoncr/tourmaline
+    version: ~> 0.28
+
+development_dependencies:
+  webmock:
+    github: manastech/webmock.cr
+    version: ~> 0.9