docs: restore the agent artifacts to the setup skill's templates

[lesnik512]

Brings this repo's agent artifacts back to the setup skill's seed templates. They had drifted —
sections renamed and reordered, wording rephrased, and in places an older copy of the template than
the skill now ships (for example issue-tracker.md predates the wayfinding section).

Template-owned wording is restored verbatim. Anything the template has no slot for is kept: sections
this repo added are carried over unchanged, and repo-specific facts inside template sections are
preserved rather than reset away.

AGENTS.md moves from a bulleted variant to the block the skill writes: one ### sub-block per
artifact, each a one-line summary and a pointer.

[github-actions]

Benchmark gate

✅ gate passed

scenario	msg/s	delete/msg	WALrec/msg	WALB/msg	fpi	upd	del	dead_tup
consumer/w1/b10	975	1.000	6.79	917	242	5000	5000	10000
consumer/w1/b100	985	1.000	6.83	920	243	5000	5000	10000
consumer/w2/b10	1130	1.000	6.80	965	242	5000	5000	10000
consumer/w2/b100	1312	1.000	6.73	954	243	5000	5000	10000
consumer/w4/b10	1000	1.000	6.82	995	261	5000	5000	10000
consumer/w4/b100	1481	1.000	6.86	1033	244	5000	5000	10000
consumer/w1/b100/tfbs100	5324	0.010	6.07	1116	243	5000	5000	10000
producer/w1/b100	2056	0.000	3.04	584	0	0	0	0

Gated (fails the build): delete_calls + tuple counters (upd/del/ins) + the producer's insert_calls, exact; select_calls within +2; wal_records within a 10% band. msg/s, WAL bytes and total calls are informational (timing/FPI noise).