Text backup start latency — Railspike diagnostics

Timestamp: 2026-10-26T17:49:57Z Step: 1 handoff Debug mode: enabled; inherited from project marker for this new cycle

Necessary/useful instructions

Source: Step 1 / Objective and Review and revision. Comparing warm-path optimization, prebuilding and streaming makes their different completeness/recovery costs visible. Retain the comparison and explicit approval gate. Source: Effort estimation / frozen-reference verification. Exact host-local hashes were verified; source exposure and missing pristine intake are disclosed rather than reconstructed. Retain provenance rules.

Redundant/unnecessary instructions

No supported findings.

Inapplicable instructions

Source: RAILSPIKE.md / Step 4 branch and commit cadence. No implementation or planning commit is authorized in Step 1; these gates remain applicable later.

Uncertain assessments

Source: Step 1 / one-page limit versus extended estimates and study snapshots. Required state, alternatives and estimate provenance lengthen the assessment; compact metadata limits repetition. Consider a standard linked checkpoint appendix if repeated cycles show readability costs. No workflow change made.

Production bottleneck remains unknown. Source inspection identifies candidates and is not deployed timing evidence.