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The Core Architecture Stack
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Nube is implemented as a single-binary Go application utilizing the following technical layer architecture.

Layer 0: Crypto-Primitives & Identity
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*  **Hash Function:** BLAKE3. Standard for Nube Content Identifiers (CIDs).
*  **Encryption:** XChaCha20-Poly1305 AEAD.
*  **Identity:** Ed25519 cryptographic keypairs for self-sovereign peer identification.
*  **Traceability:** Implements `[FUNC-CORE-INTEGRITY]` and `[FUNC-SWARM-IDENTITY]`.
*  **Identifier:** `[TECH-CRYPTO]`

Layer 1: Content-Addressable Storage (CAS)
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*  **Chunking:** FastCDC (Content-Defined Chunking). Cuts files into variable-sized chunks based on content boundaries.
*  **Addressing:** Content addressed by Blake3-hashed CIDs.
*  **Integrity Validation:** Every chunk is verified against its hash during ingestion.
*  **Traceability:** Implements `[FUNC-CORE-DEDUPLICATION]` and `[FUNC-CORE-INTEGRITY]`.
*  **Identifier:** `[TECH-BLOCKSTORE]`

Layer 2: The Merkle Directed Acyclic Graph (DAG)
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*  **Serialization:** Protocol Buffers (Protobuf).
*  **Structure:** Directories and files are represented as recursive Merkle DAG trees.
*  **DOS Hardening:** Node width limits (4096 links max) and node size limits (2MB max).
*  **Traceability:** Implements `[FUNC-CORE-INTEGRITY]`.
*  **Identifier:** `[TECH-MERKLE-DAG]`

Layer 3: Metadata & Key-Value Persistence
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*  **Type:** Delta-State Observed-Remove Set (OR-Set) Conflict-Free Replicated Data Types (CRDTs).
*  **Persistence Store:** BadgerDB for local personal deployments; configured for transactional safety.
*  **Traceability:** Implements `[FUNC-SYNC-FABRIC]` and `[FUNC-DYNAMIC-SHARING]`.
*  **Identifier:** `[TECH-METADATA-CRDT]`

Layer 4: Transport Protocol & Discovery
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*  **Stack:** libp2p over UDP/QUIC.
*  **Discovery:** Local mDNS broadcasts and global Kademlia DHT peer routing tables.
*  **Messaging:** Length-delimited Protobuf streams with a 2MB maximum limit.
*  **Traceability:** Implements `[FUNC-P2P-DISCOVERY]` and `[FUNC-SYNC-FABRIC]`.
*  **Identifier:** `[TECH-TRANSPORT]`

Layer 5: Virtual Filesystem (FUSE)
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*  **FUSE Mount:** Go FUSE API mapping filesystem syscalls (read, write, mkdir, rename, unlink) to Blockstore CAS and CRDT updates.
*  **Traceability:** Implements `[FUNC-FUSE-MOUNT]`.
*  **Identifier:** `[TECH-NATIVE-FUSE]`

Layer 6: React Web Client & Local Server
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*  **Architecture:** Local HTTP REST API served by the Go binary, communicating with a built Vite/React client using Lucide-React and TailwindCSS.
*  **State Reactivity:** Server-Sent Events (SSE) stream browser updates.
*  **Traceability:** Implements `[FUNC-WUI-BROWSER]`.
*  **Identifier:** `[TECH-WUI-DESKTOP]`

Layer 7: Dynamic Share & Swarming Engine
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*  **Live Share Registry:** Ephemeral key generation, signed DHT pointer records.
*  **PubSub Live Sync:** libp2p PubSub gossip network for live directory updates.
*  **Swarming:** Concurrently fetch block chunks from multiple DHT-resolved peers with configurable limits.
*  **Quota Safety:** Pre-flight space checks using system statfs calls.
*  **Traceability:** Implements `[FUNC-DYNAMIC-SHARING]`, `[FUNC-SWARM-SEEDING]`, and `[FUNC-SWARM-SYNC]`.
*  **Identifier:** `[TECH-SWARM-ENGINE]`