fix(a2ml): dedupe — keep descriptiles/, retire the 6a2/ copies

Owner ruling 2026-08-27: 6a2/ is retired; descriptiles/ is canonical. descriptiles
holds the files that DESCRIBE the repo's state; contractiles holds the contracts
being honoured. Where both directories held a file, the descriptiles copy is kept.

⚠ EVERY REMOVAL IS ACCOUNTED FOR BELOW. The copies differed - they were not
duplicates - so this is not a no-op cleanup:

AGENTIC (both real; removed 6a2 34L, kept descriptiles 51L)
ECOSYSTEM (removed 6a2 copy was REAL, 20L; kept descriptiles copy is TEMPLATE RESIDUE, 45L)
META (both real; removed 6a2 27L, kept descriptiles 53L)
NEUROSYM (both real; removed 6a2 21L, kept descriptiles 23L)
PLAYBOOK (both real; removed 6a2 26L, kept descriptiles 137L)
STATE (removed 6a2 copy was REAL, 38L; kept descriptiles copy is TEMPLATE RESIDUE, 64L)

Two of these are a real loss: the removed 6a2 copy held this project's own content
while the kept descriptiles copy is un-instantiated rsr-template-repo residue. That
is what the ruling selects for, and it is recorded here rather than dropped
silently. The removed content remains in git history at the parent commit.

Estate-wide this affects 5 repos: 007, 007-lang, frayed-knot-toolkit, lithoglyph,
_pathroot. Measured across all of them: prefer-descriptiles loses real content in
19 file-pairs, drops a second real copy in 29 more, and correctly drops template
residue in ZERO cases.

Author: hyperpolymath