docs: collapse single-file docs/adrs into docs/rfcs

[trilamsr]

Summary

The docs/adrs/ directory held one file (0001-metrics-to-logs-pattern-input.md). A single-file decision-record directory sitting parallel to docs/rfcs/ (13 RFCs + README + template) is taxonomy drift — operators and contributors had to learn two near-identical conventions for "load-bearing architectural decision in tree."

This PR collapses the split.

What changed

• ADR-0001 → RFC-0014 (docs/rfcs/0014-metrics-to-logs-pattern-input.md). Content reformatted to match the RFC template's section headings (Summary / Motivation / Proposal / Alternatives / Open questions / Migration / References). The substance (Option A vs Option B vs Option C analysis, the v0.130 contrib survey, PR-A landed + PR-B pending sequencing) is preserved verbatim — this is active design for issue Recipe extension: emit hw.gpu.nvlink.* + wire metrics path for pattern-1 detector #260 PR-B, not archaeology.
• docs/adrs/ directory removed.
• 6 cross-references repointed at the new RFC path:
  • docs/README.md (subdirectories table — adrs/ row removed)
  • docs/ATTRIBUTES.md (2 spots: tracecore.alert.pcie_rate_collapse.* row + "See also" link)
  • docs/integrations/prometheus-scrape.md (2 spots)
  • docs/patterns/pattern-4-thermal-throttle.md
  • docs/patterns/pattern-5-pcie-aer.md
• 5 source-code comments repointed (module/processor/patterndetectorprocessor/{patterndetector.go,thermal_throttle_test.go}, module/pkg/patterns/{pcie_aer.go,thermal_throttle.go}).
• docs/rfcs/README.md status-index gains an RFC-0014 row (accepted, 2026-05-31).

Why convert (not delete)

ADR-0001 was evaluated against the "delete if RFC-0013 already covers it" bias. It is not covered:

• RFC-0013 §5 mentions a metricthresholdconnector as a contribution slot in one bullet. It does not evaluate Option A vs Option B vs Option C, cite the contrib v0.130 evidence, or sequence the PR-A/PR-B split for the metric-sourced detectors.
• ADR-0001 is the binding design contract for patterns ci(deps): bump the gh-actions group with 5 updates #1 / Add NORTHSTARS, RFC-0002, and Q1 MILESTONES #3 / Wave 1: governance bootstrap (CODEOWNERS, DCO, signing) #4 / Apply Wave-1 follow-ups: tests, automation, doc-truth #5 (4 of the next NORTHSTAR detectors). Source code (pcie_aer.go, thermal_throttle.go, patterndetector.go) cites it as the reason for the staged-but-quiet wire-up.

Delete would orphan 5 source comments and break the audit trail for an active design decision. Convert keeps the record load-bearing without preserving the parallel taxonomy.

Verification

• grep -rn "docs/adrs\|adrs/0001" returns 0 hits.
• grep -rn "ADR-0001\|ADR 0001" returns 0 hits.
• ls docs/ | grep -i adr returns empty.
• pre-commit golangci-lint + go vet + go mod verify clean.

docs: collapse single-file `docs/adrs/` into `docs/rfcs/`. ADR-0001 (metrics-sourced pattern inputs) is promoted to RFC-0014 verbatim; cross-references across docs and module source repointed.

Test plan

• grep -rn "docs/adrs" returns 0 hits
• grep -rn "ADR-0001" returns 0 hits
• docs/adrs/ directory removed
• golangci-lint + go vet clean (pre-commit hook)
• CI green