docs: add checkpoint files for state tracking

Add STATE.scm, ECOSYSTEM.scm, and META.scm for project state management:
- STATE.scm: Current project state, tasks, blockers, milestones
- ECOSYSTEM.scm: Relationships to other projects in ecosystem
- META.scm: Architectural decisions and development practices

These files enable AI assistants and tools to understand project
context and make informed decisions about changes.

Part of RSR (Rhodium Standard Repository) compliance.

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

Author: Test

ECOSYSTEM.scm

@@ -0,0 +1,23 @@
+;; SPDX-License-Identifier: PMPL-1.0-or-later
+;; ECOSYSTEM.scm - Ecosystem relationships for proof-of-work
+;; Media type: application/vnd.ecosystem+scm
+
+(ecosystem
+  (metadata
+    ((version . "1.0.0")
+     (name . "proof-of-work")
+     (type . "cryptography-tool")
+     (purpose . "Part of hyperpolymath tool ecosystem")))
+  
+  (position-in-ecosystem
+    "Provides cryptography-tool functionality within the hyperpolymath suite")
+  
+  (related-projects
+    ((disinfo-nesy-detector . "verification-consumer")))
+  
+  (what-this-is
+    "proof-of-work is a specialized tool in the hyperpolymath ecosystem")
+  
+  (what-this-is-not
+    "Not a general-purpose framework"
+    "Not intended as standalone product"))

META.scm

@@ -0,0 +1,27 @@
+;; SPDX-License-Identifier: PMPL-1.0-or-later
+;; META.scm - Meta-level information for proof-of-work
+;; Media type: application/vnd.meta+scm
+
+(define meta
+  `((metadata
+      ((version . "1.0.0")
+       (schema-version . "1.0")
+       (created . "2026-01-30")
+       (updated . "2026-01-30")
+       (project . "proof-of-work")))
+    (architecture-decisions
+      ((adr-001 . ((status . "accepted")
+                   (date . "2026-01-30")
+                   (context . "PoW algorithms with formal verification")
+                   (decision . "Use Rust for performance and safety")
+                   (consequences . "Faster execution, memory safety, steep learning curve")))))
+    (development-practices
+      ((code-style . "rustfmt default")
+       (security . "cargo-audit, ClusterFuzzLite")
+       (testing . "cargo test, fuzzing")
+       (versioning . "semantic versioning")
+       (documentation . "rustdoc")
+       (branching . "GitHub Flow")))
+    (design-rationale
+      ((why-rust . "Performance, safety, ecosystem")
+       (why-github-actions . "CI/CD automation, security scanning")))))

STATE.scm

@@ -1,4 +1,4 @@
-;; SPDX-License-Identifier: PMPL-1.0
+;; SPDX-License-Identifier: PMPL-1.0-or-later
 ;; STATE.scm - Project state for proof-of-work
 
 (state