The guard's case-insensitive lane lookup (rows_named_ci_alias) and session-start's (lane_named_ci) still read an unreadable register as no row (follow-up to #310) #315

The follow-up named in #310's design (R5, #310 6350725057) and in lane 3's review of it (#310 6351763793: R5 and NIT 587). It is filed on Brett Heap's approval, given in lane 3's session at about 21:44Z on 2026-10-22.

#310 makes canon_lane refuse every name over an unreadable register (Brett's R1, "Refuse", #310 6351997987). The two case-insensitive lookups below are outside that change.

What is wrong

• lane_named_ci (lanes-edit.sh:6679 at 33ce26d). A lane name typed in another case resolves only through a readable register row: over an unreadable register, or for a lane known only by its log or archive row, lane-state, lane-trees and worktrees answer 8 (none) (from #290) #310's design found that it still reads an unreadable register as "no row". Session-start reaches it at :9253.
• rows_named_ci_alias (:5573 at 33ce26d). Lane 3's review found that the guard resolves a typed name through this function (:10655 and :10694 at bc825a4), not through lane_named_ci. It needs the same check.
• Second lifecycle directories. Any that the old case bug filed (for example REPOB-1/ beside repoB-1/) are not repaired by A lane name typed in another case resolves only through a readable register row: over an unreadable register, or for a lane known only by its log or archive row, lane-state, lane-trees and worktrees answer 8 (none) (from #290) #310.

Direction

• The rule. Give both lookups A lane name typed in another case resolves only through a readable register row: over an unreadable register, or for a lane known only by its log or archive row, lane-state, lane-trees and worktrees answer 8 (none) (from #290) #310's rule: an unreadable register means "could not be read" (66, or the caller's own refusal), never "no row".
• The test. Pin each lookup with the register moved aside.
• The old directories. Decide whether to repair them, or only to report them.
• Review. Lane 3 reviews the design before any code.

Not started: v1.2.0 work waits for the v1.1.0 tag and Brett's word.