[SoundMatt]

Summary

Implements ROADMAP.md milestone 45, "RC Server Lifecycle & Register-Map Model (v2.1.0)" — the next item in Phase 13's TC18 protocol-replacement sequence, following milestone 44's wire-format core (v2.0.0).

• include/rcp/lifecycle.hpp — the 3-state RC Server lifecycle machine (HW_UNCONFIGURED/HW_CONFIGURED/RCP_CONFIGURED), forward-only single-step advance() transitions, the HW_CFG_INCONSISTENT/RCP_CFG_INCONSISTENT plausibility checks gating each transition, an explicit deconfigure() backward path, and independent generic/functional config-block locking queries.
• include/rcp/regmap.hpp — the register-map data model: the generic/functional endpoint config split, general bootstrap fields (magic, protocol version, vendor/device ID, endpoint count, stream/queue capacity, svr_implemented_options, and the five table pointer/capacity fields), HW pin-map config, request-stream config (including the rx_wd_*/rx_safety_measure fields, present but intentionally inert until v2.6.0), the EP-ID/byte_bus_id mapping table (client-ordering risk flagged explicitly in comments), response/ack queue config, and persistent 8-bit sequencer-state storage — plus Ep0, the RC Server pseudo-endpoint implementing whole-register-map read (unrestricted) and write (root-client-only), and per-endpoint write restriction for every other client.
• The four mandatory register-map error codes (UNAUTHORIZED_ACCESS, LOCKED_MEM_ACCESS, REQUEST_REJECTED, INVALID_PARAMETER) as rcp::regmap::RegMapErrc.
• New coverage: tests/test_lifecycle.cpp (REQ-LIFECYCLE-001..006) and tests/test_regmap.cpp (REQ-REGMAP-001..014), both traced in .fusa-reqs.json.
• Version bumped to 2.1.0 (version.hpp, CMakeLists.txt); ROADMAP.md milestone 45 checked off with a "Done (v2.1.0)" note following the milestone 44 precedent.

rcp/wire.hpp and rcp/legacy_wire.hpp are untouched, per the milestone's own scope note. rcp/rcp.hpp's pre-replacement Zone/Command/Controller/Registry model is left in place, unmodified in behavior — only its header comment now points at the new replacement headers — since roughly three dozen other headers still build against it and aren't rebound until their own later milestones (v2.9.0 onward per the Release Plan); see the Satellite Package Disposition table. Full removal of rcp.hpp's old model in one PR would have broken the whole tree for no benefit to this milestone's scope.

Field widths, the register-map magic-number value, and locking policy are this implementation's own design choices for realizing the described behavior — no text from the source specification is reproduced anywhere in code or comments, consistent with wire.hpp's existing conformance disclaimer.

Test plan

• cmake --build (Release + Debug, C++17 and C++20, AppleClang locally) — clean, no new warnings
• ctest — all 44 suites pass, including the two new ones (43 + 77 assertions)
• RELAY conformance gate (relay conform --strict against the built cpp-rcp CLI) — PASS
• cpfusa check — 0 errors
• cpfusa lint — 0 errors (info/warning counts unchanged from baseline pattern)
• cpfusa cyber — 0 errors
• cpfusa trace --req-coverage 100 — all new REQ-LIFECYCLE-/REQ-REGMAP- entries show impl:[✓] test:[✓]
• cpfusa verify — ctest evidence generated, 44/44 passed
• CI (waiting on this PR's GitHub Actions run)