v4.23.0 — Beat Grep where the model reaches for it

Same benchmark as v4.22.0 (tsbench --reel, Haiku, 8 tasks, same evening),
three arms:

	cost	new tokens	sessions using TS	wall time
no Token Savior	0.234 $	99 993	—	134 s
v4.22.0 auto	0.202 $ (-14 %)	75 470	5/8	195 s
v4.23.0 auto	0.129 $ (-45 %)	43 660 (-56 %)	8/8	210 s

One pass per task, variance not measured. Wall time is still higher than the
baseline: each benchmark session starts a fresh server that indexes the repo.

• search_codebase names the symbol containing each hit (in). "Who
  calls X" is answered in one call; Grep cannot do that, and that is where
  the model kept choosing Grep.
• read_lines names the symbol holding the first line when none covers
  the whole range. "Which function is line 145 in" took three reads: the
  default 60-line window spilled into the next function and no name came out.
• Descriptions of search_codebase, find_symbol, get_function_source
  and read_lines rewritten around what they do better than Grep and Read
  (+37 tokens on the manifest).
• ts gain and the dashboard stop inflating savings. The native cost of
  a call was a fraction of the whole project (15 % for a search, 30 % for
  get_full_context), hence "98.7 % saved". It is now the real alternative:
  the file holding the symbol, the whole file for structure tools, and as
  much as the answer for a search or a line range. Sessions carry their
  method (naive_method=2); only that method is summed, and the output
  recalls the end-to-end measurement.
• Memory hooks: no more chmod/restart traces, nothing injected off
  topic. Over 7 days, 83 % of memories injected with each prompt were
  automatic traces ("chmod on …", "restart …"), 13.5 % shared a meaningful
  word with the prompt, and none was cited or recalled by the model.
  memory-posttooluse.sh no longer captures systemctl start|restart|… or
  chmod|chown; memory-userprompt.sh injects only non-trace memories that
  share a 5+ letter word with the prompt, and nothing otherwise.
• Discipline guard matcher now sends get_function_source,
  get_class_source and ts_execute to the guard, so reading a symbol counts
  as context as v4.22.0 intended; a test keeps matcher and rule aligned.