docs(tasks): rebuild the board as TASKS_DUMP.md — the Task API is gone

The Claude-Code Task API is not reachable from this session (TaskList/TaskCreate/
TaskUpdate/TaskGet all absent), so the live board — last seen at 112 tasks —
could not be read or rewritten. Rebuilt the tree from durable sources instead:
board-archive.md (ids exact, completed through 2026-07-29), the numbered
achievement logs, the memory store, and git.

Structured as six epics with the work nested underneath: OPAL-26 release (the
only one blocking a shipment), cut/boundary detection, the floor problem, rig &
hardware, open taste calls, completed. Each item carries the measurement or the
quote that justifies it rather than a bare title, so it survives a cold read.

Honest about provenance: ids in the #150+ range come from the lost board via
session context and cannot be re-verified, so the file says to treat a #17x
number as a name, not a key.

This session's outcomes are slotted in place: #1's leading silence measured
(1.452s), the timbral cut lens declared a dead end with its three-attempt table,
and #13/#15 escalated to ear-only calls.