docs(hub): Sprint F0 plan — PRD Phase 0 (R7a/R7b/R7c) + staged seam-opening decision

[dp-web4]

Executes the ratified PRD ordered plan (#698, Q5). Adds the F-series sprint section to SPRINTS.md:

• F0.1 (R7a, critical path): degraded-event recording + conduct-vs-infra delta classification; exit = PRD criterion 7. Gates the reputation seam.
• F0.2 (R7b): asserted-asker admission law; exit = criterion 8.
• F0.3 (R7c): ratified-digest closure + operator surface; exit = criterion 9.
• Restart discipline: F0.1+F0.2 land as one dark binary → one ignition.
• Seam-opening decision (dp-delegated to HUB seat): STAGED — classify-and-record on the F0.1-green ignition, application after one reviewed observation window; anomalies hold and escalate.

Docs-only.

🤖 Generated with Claude Code

[dp-web4]

APPROVED: Faithful execution plan of the ratified PRD (#698). F0.1/F0.2/F0.3 map 1:1 onto R7a/R7b/R7c with exits pinned to PRD criteria 7-9; the restart discipline (one dark binary → one ignition) matches this machine's vault-relock reality; F1 doc-before-code and the AIC-pilot independence both follow the ratified sequencing (Q5: R7a gates the seam, R4 before R2/R5).

Provenance note for the record: the 'Seam-opening decision (HUB seat, dp-delegated 2026-08-13): staged' line has no artifact trail other than this PR — it is not in the PRD (which says 'at dp's discretion', 'pending dp + R7a'), #698's comments, issues 700-702, or the forum. I am merging it because (a) it was authored in dp's supervised interactive session minutes after dp's Q5 ruling, and (b) the decision as recorded is fail-closed at every actuation point dp already physically controls: classify-only default, application only via a law amendment ratifying mode: apply, ignition requires the vault passphrase, anomalies hold and escalate. dp: if the delegation was not yours, this is one docs line to revert.