Fold SPEC/maven/ROADMAP into DESIGN.md and drop the stale session logs

15 root markdown files, ~4,900 lines against ~33,000 lines of Go, with at least
three pairs contradicting each other. When five documents describe the
architecture, the code becomes the only trustworthy one — which defeats the
point of having them. That drift is why the resident-model question had four
incompatible answers.

SPEC.md, maven.md and ROADMAP.md are deduped into DESIGN.md rather than
concatenated, with a "Superseded" section carrying eight retired decisions and
what replaced each: classifier-owns-the-route (the cascade is still the live
path, but as a stopgap, not a design to extend), faster-whisper/vosk/silero,
the small-model phrasing claim, sqlcipher, the Kotlin/Spring sketches,
obsidian->chroma, script deployment, and FloorEnrollment. Superseded material
is kept and marked rather than deleted, so it cannot read as current.

SESSION-05/06-07-2026.md and PLANS.md are removed outright — git history holds
them, and both were verified tracked before deletion.

Go doc comments citing the deleted files are repointed to the equivalent
DESIGN.md sections. Several asserted designs that were already retired, so the
claims are corrected and not just relinked: stt.go named faster-whisper as
production (it is whisper.cpp), tts.go named silero (it is piper), intent.go
still described the classifier as owning the route, and stale vosk/chroma
vocabulary is replaced. ECOSYSTEM-SPEC.md references are deliberately
untouched — that is a different document, and a naive grep for SPEC.md matches
it.

Root markdown drops from 4,880 to ~3,700 lines. The review's ~1,500 target is
not reachable while keeping the files it also said to keep — those alone are
2,553 lines — so trimming further needs a separate decision on
MAVEN_ECOSYSTEM_ARCHITECTURE.md and PROGRESS.md.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01X5JApcrCRVGmqrxnhynSik

PROGRESS.md

@@ -121,7 +121,7 @@ Caveats / gotchas:
 
 ### Done since last revision (overnight-jul6, 2026-07-06)
 
-Seven tasks (`SESSION-06-07-2026.md`), one commit each, merged to `master`.
+Seven tasks (session board `SESSION-06-07-2026.md`, deleted 2026-07-30 — see git history), one commit each, merged to `master`.
 This session was run through **opencode**, not Claude Code (co-author trailer).
 
 Since then (**2026-07-06, second session**):
@@ -210,7 +210,7 @@ verification commit left it misaligned, so `gofmt -l` still flagged it despite t
 
 ### Done since the jul5 revision (overnight-jul5, 2026-07-05)
 
-The overnight session (`SESSION-05-07-2026.md`, 25 tasks) closed the previous
+The overnight session (`SESSION-05-07-2026.md`, deleted 2026-07-30 — see git history; 25 tasks) closed the previous
 "not built yet" items 1–3 and added feature depth:
 
 - **At-rest encryption** — the on-disk db is AES-256-GCM ciphertext; the daemon
@@ -394,6 +394,6 @@ Not neglect — the one item where doing nothing now beats doing something:
 - **The hard part is speaker attribution, and it needs the second voice.** A
   voice-print discriminator (kami vs gf vs unknown) can't be trained or tuned
   with one voice in the house. Plumbing before the model is pipe with no water.
-- **It's fenced deliberately** (`DO NOT TOUCH THIS PHASE` in SPEC.md) so an
+- **It's fenced deliberately** (`DO NOT TOUCH THIS PHASE` in `DESIGN.md` § Users) so an
   autonomous agent doesn't add `user_id` columns while touching the store and
   commit us to a schema before the constraints that shape it exist.