docs: link ticketed spikes (#67-#76) from BACKLOG open-items

[LegalMarc]

Adds issue-number pointers to the three now-ticketed BACKLOG open-items so the list reflects what's ticketed vs still unticketed.

• God Module in Python (docx_io split) → docx_io split: golden-file characterization harness (prereq for all slices) #70, docx_io split: scan/hardening/order-dependency characterization tests (prereq for slices 4-5) #71 (prereqs) + slices docx_io split - Slice 1: extract settings.py (CLI/settings config) #72–docx_io split - Slice 5: hardening.py + revisions + document.py coordinator + shim #76
• Fragile Swift-to-Python Bridge → Bridge schema: pydantic models + validate-before-write for the 3 report shapes #67 (step 1); later Swift/tuple/progress steps noted as unticketed
• Redaction Rationale Reporting → Redaction rationale: data layer (Option B, opt-in, cluster-level, all mitigations) #68 (data) + Redaction rationale: HTML report rendering (AI-inferred vs rule-match badges) #69 (UI)

Docs-only; no code paths touched.

🤖 Generated with Claude Code

[LegalMarc]

Closing as superseded rather than merging.

Every item this PR annotates has since shipped, so the pointers would land already out of date:

• God Module in Python — the docx_pkg/ split completed across docx_io split - Slice 1: extract settings.py (CLI/settings config) #72-docx_io split - Slice 5: hardening.py + revisions + document.py coordinator + shim #76. docx_io.py is now a re-export shim. The entry moved to the shipped list on 2026-09-09.
• Fragile Swift-to-Python Bridge — this PR notes the later steps as unticketed. They were ticketed and landed on 2026-09-10 as Bridge schema step 2: decode the failure report into a typed Swift struct #89 through Bridge schema step 5: validate metadata settings decoded from the environment #94, covering Swift Decodable readers, the return-tuple payloads, the progress-callback schema and the environment-variable blobs. All five migration steps in the design spike are now done.
• Redaction Rationale Reporting — Redaction rationale: data layer (Option B, opt-in, cluster-level, all mitigations) #68 and Redaction rationale: HTML report rendering (AI-inferred vs rule-match badges) #69 both closed; the backlog already records both directions as closed with no further work planned.

It also conflicts with main, since the same lines were rewritten when the backlog was corrected.

No content is lost: the ticket history it wanted to record is in the closed issues and in docs/reports/2026-09-09-deep-bug-sweep-remediation-status.md.