ch32v: board-data and docs nits — X035 clock_source, V208 variant reuse, BOARD_STATUS drift, dead get_linker_script, missing WCH datasheets

[zackees]

Part of the CH32V pipeline audit (#1102). Grab-bag of LOW-severity data/doc/code inconsistencies found along the way — none is load-bearing today, each is a landmine for the next person.

1. genericCH32X035C8T6.json says "clock_source": "hsi+pll" — the CH32X035 has no PLL (and no HSE); it runs the 48 MHz HSI directly. Harmless today because nothing consumes clock_source, but wrong reference data. Should be "hsi".

2. genericCH32V208WBU6.json reuses the CH32V203 variant: "variant": "CH32V20x/CH32V203C8", "variant_h": "variant_CH32V203C8.h". The V208 is a different die (BLE radio, different pinout). Currently semi-moot because the env builds Arduino-core anyway (see ch32v: framework field is ignored — noneos-sdk envs silently build the OpenWCH Arduino core (4 of 9 CI envs affected) #1108) and no V208 variant exists upstream, but the JSON presents a V203C8 pin map as if it were the V208's.

3. docs/BOARD_STATUS.md CH32V section is out of date both directions: the badge list has only ch32v003/103/203/208/303/307 (missing ch32v006, ch32l103, ch32x035, which have workflows), and the "Supported" list names only CH32V003 while nine families build in CI. It also says "Supported" with no build-only caveat even though deploy is unimplemented (ch32v: deploy is unimplemented while board JSONs advertise wch-link/minichlink/isp/wlink and docs say Supported #1105).

4. Dead divergent code: Ch32vCores::get_linker_script() (crates/fbuild-library/src/library/ch32v_core.rs) resolves a .ld from the variant directory, but the orchestrator resolves system/<series>/SRC/Ld/Link.ld and never calls this method. Two resolution strategies, one unused — delete or unify (relevant when fixing ch32v: V20x links against Link.ld defaults (64K/20K) — stack pointer beyond physical RAM on CH32V203C6/G6, RB/208 capped at half #1103/ch32v: CH32V006 builds as a CH32V003 — series mapped to system/CH32V00x instead of CH32VM00X (16K/2K linker script on a 62K/8K chip) #1104).

5. FastLED/datasheets has no wch/ folder. The audit had to verify chip memory maps against the upstream OpenWCH core and WCH's site. Add CH32V003 / CH32V006 / CH32V103 / CH32V203 / CH32V208 / CH32V30x / CH32X035 / CH32L103 datasheets + reference manuals there (same layout as espressif/soc/*) so board JSONs and future audits can cite pinned PDFs.

Severity: LOW.