docs: unify ADR/RFC trees into one lifecycle-organized RFC tree

Collapse docs/adr/ and docs/rfc/ into a single docs/rfc/ with proposed/,
implemented/, and rejected/ subfolders. Every file is renamed to
yyyy-mm-dd-topic-title.md, where the date is when the topic was first
proposed (from git history). ADRs and RFCs that covered exactly the same
topic are merged (property-based testing, session persistence); the
umbrella RFC 005 stays split across its three implemented decisions, and
RFC 006's deferred part-3 (API extractor reports) splits into its own
proposed RFC. All cross-references become machine-checkable relative
links instead of bare "ADR NNNN" / "RFC NNN" prose.

Add a verify-md-links doc-sync gate (scripts/verify-md-links.ts) that
checks every relative Markdown cross-link resolves, wired into doc-sync
alongside verify-md-wrap. This makes the reorganization self-verifying:
the same change that rewrote ~forty inter-doc links adds the check that
proves none dangle. Document the cross-link convention in a new
docs/AGENTS.md and record the gate as an implemented RFC.

doc-sync, typecheck, lint, and the full test suite (667) all pass.

packages/agent-loop/tests/coverage-edges.spec.ts

@@ -301,7 +301,7 @@ describe('disposed vs aborted branching', () => {
   })
 })
 
-describe('structured tool error propagation (RFC 005 pt 2)', () => {
+describe('structured tool error propagation (the runtime-validation RFC, part 2)', () => {
   it('forwards a tool HarnessError onto the tool/result session event', async () => {
     const { HarnessError } = await import('@deepseek-ai/dsh-llm')
     // First model turn calls the tool; second turn (after the tool result is

packages/agent-loop/tests/properties.spec.ts

@@ -1,8 +1,8 @@
 /**
- * Property-based tests for the agent loop's inbox/turn scheduling (RFC 001 →
- * ADR 0013). Deterministic by construction: schedules are driven through the
- * `agent/status` settle signal (no wall-clock sleeps), so a flake is a finding,
- * not timing noise.
+ * Property-based tests for the agent loop's inbox/turn scheduling (the
+ * property-testing RFC). Deterministic by construction: schedules are driven
+ * through the `agent/status` settle signal (no wall-clock sleeps), so a flake
+ * is a finding, not timing noise.
  *
  * Invariants: every sent message appears exactly once in the log (none lost);
  * turn numbers strictly increase; status transitions follow the legal machine

packages/agent-loop/tests/resume.spec.ts

@@ -39,7 +39,7 @@ function waitForIdle(ctx: Context, agent: LoopAgent): Promise<void> {
   })
 }
 
-describe('RFC 009: AgentLoop factory create/resume', () => {
+describe('the session-persistence RFC: AgentLoop factory create/resume', () => {
   it('createAgent uses the caller-supplied sessionId (not ${id}-session)', async () => {
     const adapter = new MockAdapter([textResponse('hi')])
     const { ctx } = await persistentHarness(adapter)
@@ -128,7 +128,7 @@ describe('RFC 009: AgentLoop factory create/resume', () => {
 
   it('an idle inject() is flushed durably on its own (survives without explicit flush/dispose)', async () => {
     // Lifecycle 1: run a turn, then inject context while idle. The idle inject
-    // wraps its context/message in a one-shot turn AND checkpoints it (ADR 0017)
+    // wraps its context/message in a one-shot turn AND checkpoints it (the turn-enclosure RFC)
     // — without an explicit flush or clean dispose, the notice must still reach
     // disk, since a crash before the next turn would otherwise lose it.
     const adapter1 = new MockAdapter([textResponse('answer')])

packages/agent-loop/tests/review-fixes.spec.ts

@@ -619,7 +619,7 @@ describe('P1-6: step/start is appended before agent/step-start is emitted', () =
     const agent = ctx.agentLoop.create('a-step-order', { model: 'mock' })
 
     // Capture, at the moment agent/step-start fires, whether the matching
-    // step/start event is already in the log (append-before-emit, ADR 0003).
+    // step/start event is already in the log (append-before-emit, the event-sourcing RFC).
     const observed: { turn: number; step: number; lastEventType: string | undefined; sawStepStart: boolean }[] = []
     ctx.on('agent/step-start', (subject, turn, step) => {
       if (subject !== agent) return
@@ -828,7 +828,7 @@ describe('P1-5: a started turn (and any open step) is always closed on a boundar
     // loop must therefore still owe (and append) a turn/end — deciding "owed"
     // from the log via isTurnOpen, not a "turn started" flag that the throw
     // skipped. Otherwise the turn stays permanently open and poisons the next
-    // turn/replay (ADR 0017). (Uses the plain harness — NOT the invariants
+    // turn/replay (the turn-enclosure RFC). (Uses the plain harness — NOT the invariants
     // oracle — because the throwing listener is itself a session/event
     // subscriber.)
     const adapter = new MockAdapter([textResponse('turn 2')])
@@ -868,7 +868,7 @@ describe('P1-5: a started turn (and any open step) is always closed on a boundar
     // Regression: a normal turn completes, closeTurn(true) appends turn/end and
     // emits agent/turn-end whose listener throws. The error must NOT be appended
     // as a session event after turn/end — that would sit past the commit
-    // boundary and be dropped as a crash tail on resume (ADR 0017). It is
+    // boundary and be dropped as a crash tail on resume (the turn-enclosure RFC). It is
     // surfaced via agent/error instead, and the log's last event is turn/end.
     const adapter = new MockAdapter([textResponse('done'), textResponse('next ok')])
     const ctx = await balancedHarness(adapter)