chore(cleanup): remove the June trials, orchestrator docs, dormant agent, caller-less code and the fix-round chain

R4-R7 of the cleanup list (decision 188): the June trial docs and
fixtures, the three orchestrator reference docs, the dormant
synthesis-agent, code with no caller (project-discovery, bash-normalize,
fidelity-diff, test-census, the next-session prompt validator, arm B and
the --workflow flag) and the fix-round chain. Living docs repointed; the
reasons for in-session orchestration and the all-opus pin are now written
in docs/architecture.md and docs/profiles.md.

New tests/lib/living-paths.test.mjs: living tracked text names only
plugin paths that exist (seen red with 22 dead pointers before this
commit). docs/T1-cc26-delegated-orchestration.md and
lib/review/gold-scorer.mjs stay until R-b: the frozen end-state registry
names them.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

CONTRIBUTING.md

@@ -34,10 +34,9 @@ Changes to this plugin must preserve:
 | `commands/trekresearch.md` | The `/trekresearch` slash command — research orchestration |
 | `commands/trekplan.md` | The `/trekplan` slash command — planning orchestration |
 | `commands/trekexecute.md` | The `/trekexecute` slash command — execution orchestration |
-| `agents/*.md` | 24 agent files (21 spawnable + 3 orchestrator reference docs) for research, exploration, review, execution, and orchestration |
+| `agents/*.md` | 20 agent files, all spawnable, for research, exploration, review and execution |
 | `templates/plan-template.md` | Structured plan output format |
 | `templates/research-brief-template.md` | Research brief format with triangulation and confidence |
-| `templates/spec-template.md` | Spec file format |
 | `templates/session-spec-template.md` | Session spec format for a session the user opens |
 
 The command files are the core. All logic lives in markdown.