docs(roadmap): restructure sequencing (M20 phase 1, not first) + skills-as-discipline doctrine

docs/plans/ROADMAP.md

@@ -127,6 +127,46 @@ Reference: harvest worktree `~/src/mosaic-stack-worktrees/v2-harvest`
 Usurpation criteria to be defined before any replacement (proposed:
 functional parity of P0 operations on the v2 runtime + owner sign-off).
 
+### Restructure sequencing (decided 2026-09-03, owner question)
+
+The monorepo restructure is NOT done first. Reason: the bash entry points'
+final home is *replacement by* `packages/mosaic` commands, not containment -
+moving them into packages/ now, then replacing them at M20, migrates
+everything twice and churns the suites (the safety net) during peak feature
+work. Instead:
+
+1. **Layout doctrine frozen now** (this file + AGENTS.md): nothing new lands
+   at root; features build in their durable homes (`skills/`, `roles/`,
+   `docs/`, `adapters/`, `src/`).
+2. **M20 phase 1 = restructure**: `packages/` monorepo skeleton absorbs the
+   script entry points as CLI commands (`packages/mosaic`), with
+   `packages/agent`, `packages/auth` following the harvested anatomy. The
+   bash scripts retire as they are absorbed.
+3. **Succession**: at usurpation, v2 content (already in `packages/*` shape)
+   becomes the next-branch content of mosaicstack/stack.
+
+### Target tree (post-M20-phase-1)
+
+    /                        bootstrap + entry docs (unchanged)
+    +-- packages/
+    |   +-- mosaic/          the CLI: tui, yolo, skill, release, onboard, check
+    |   +-- agent/           seat/session runtime (absorbs src/ + adapters/)
+    |   +-- auth/            provider slots, account ensure (absorbs M19)
+    |   +-- config/          schema + policy validation (absorbs config tooling)
+    +-- contracts/ roles/ missions/ tasks/ templates/   declarative inputs
+    +-- skills/              shipped skills (installed to dataRoot on activate)
+    +-- docs/                plans, harvest, SESSIONS, TOOLS
+    +-- src/                 container runtime (loader, dispatcher)
+
+### Skills as discipline encoding (owner insight, 2026-09-03)
+
+Skills are not tool menus - they encode operational discipline: order of
+operations, gotchas, and failure history. The tool-race lesson and every
+catalogued defect become skill content per role (e.g. a conductor skill
+carries: sequential dependent calls; verify writes before claiming;
+symlink-ensure before TUI; path pre-checks before pi flags). Role
+contracts (M17) declare which skill subsets each seat receives.
+
 ## Explicitly deferred
 
 - CI runners (owner: Gitea hardware is slow; local suites are the gate) —