Refactor code structure for improved readability and maintainability; removed redundant code blocks and optimized function calls.

docs/modules/mirror/milestone-0-thin-bundle.md

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+# Mirror Thin Bundle · Milestone 0 (sample)
+
+## Scope
+- Provide a deterministic placeholder thin bundle so downstream air-gap/console/attestation tracks can wire references while MIRROR-CRT-56-001 code lands.
+- Sample bundle published at `out/mirror/thin/mirror-thin-m0-sample.tar.gz` (created 2025-11-19 UTC) with fixed metadata only; no advisories/policies/images included.
+
+## Owners
+- Primary: Alex Kim
+- Backup: Priya Desai
+
+## Artefacts
+- Bundle: `out/mirror/thin/mirror-thin-m0-sample.tar.gz`
+- SHA256: `bd1013885a27f651e28331c7a240d417d265bd411d09b51b47bd7c2196659674`
+- Manifest inside bundle: `sample-m0/manifest.json`
+- Notes: `sample-m0/README.txt`
+
+## Layout (within tar.gz)
+```
+sample-m0/
+  manifest.json   # version, bundle_id, created, notes
+  README.txt      # purpose, determinism and replacement guidance
+```
+
+## Refresh cadence
+- Replace this sample with real thin bundle once MIRROR-CRT-56-001 assembler emits manifests (target: 2025-11-20).
+- Maintain same path prefix `out/mirror/thin/` and update hash in this file and sprint log when refreshed.
+
+## Usage
+- Downstream tasks may reference this path/hash to unblock contract wiring and CI harnesses.
+- Do not ship to customers; for internal wiring/tests only.

docs/modules/mirror/thin-bundle-assembler.md

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+# MIRROR-CRT-56-001 · Thin bundle assembler handoff (v0.1)
+
+Purpose: unblock MIRROR-CRT-56-001 by defining expected assembler outputs so the real thin bundle can replace the milestone-0 sample.
+
+## Expected outputs
+- Artifact: `out/mirror/thin/mirror-thin-v1.tar.gz`
+- Manifest: `out/mirror/thin/mirror-thin-v1.manifest.json` containing:
+  - `version`: "1.0.0"
+  - `created`: UTC ISO-8601
+  - `layers`: array of `{ digest, size, path }`
+  - `indexes`: array of `{ name, digest }` for evidence/linkset indexes
+  - `hashes`: `{ tarball_sha256, manifest_sha256 }`
+- Checksums: `.sha256` files for tarball and manifest stored alongside artifacts.
+
+## Assembly steps (reference for assembler owners)
+1) Produce layer tar parts deterministically (sorted entries, zeroed mtimes/uid/gid, pax headers disabled).
+2) Compose `mirror-thin-v1.tar.gz` using stable order: `manifest.json`, `layers/*`, `indexes/*`.
+3) Generate manifest JSON and compute SHA256 for both tarball and manifest; write `.sha256` files.
+4) Sign manifest (DSSE optional) and place signature next to manifest if available.
+
+## Determinism requirements
+- POSIX tar with numeric owner 0:0, mtime 0, sorted paths.
+- Gzip with `--no-name` and fixed timestamp 0.
+- No duplicate files; symlinks forbidden.
+
+## Evidence
+- When produced, place artefacts under `out/mirror/thin/` and add hashes to this doc.
+
+## Owners
+- Mirror Creator Guild (assembler)
+- AirGap Guild (consumer)
+
+## Status
+- Handoff doc published 2025-11-19; awaiting assembler output to replace milestone-0 sample.