book3: update worldbuilding for ruin backstory revision

- kingdom-of-corvel.md: Holven as debt-acquirer pattern
- pip.md: rewrite as true dragon from Mine 1 earth-magic mutation,
  add growth mechanics section
- supporting-cast.md: Sable as returning forensics scout,
  add Holven row

Ref: docs/superpowers/specs/2026-04-19-book3-ruin-backstory-revision-design.md

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

characters/supporting-cast.md

@@ -19,7 +19,7 @@ Recurring characters have their own files. Minor characters are tracked in the t
 | Brennan Toor | `brennan-toor.md` | The Wolf's old Pathfinder comrade — visible Cairns node |
 | Duchess Pamira | `duchess-pamira.md` | Book 3 client, Devod's love interest |
 | Kimbra | `kimbra.md` | Phelan's mother (Book 3 reconnection subplot) |
-| Pip | `pip.md` | Pixie dragon, Mere's living magic detector (Book 3+) |
+| Pip | `pip.md` | True dragon (Mine 1 lineage), Mere's living magic detector (Book 3+) |
 
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@@ -37,11 +37,12 @@ Recurring characters have their own files. Minor characters are tracked in the t
 | Calla Floundry | Ned's wife, case client | Client | Ch11 | Active |
 | Brida Voss | Hendrick Voss's cousin. Early 30s, wiry frame, tired brown eyes. Sheltered Kae because Elara asked her to. Ground-floor tenement, southern warrens near old tannery. Provided Kae's full backstory. Recognised Phelan as "the man who burned my wall." | Witness / source | Ch14 | Active — minor |
 | Drannick | Pipe smoker outside metalworking shop in Kae's territory. Referred Phelan to Carson. | Street contact | B2 Ch05 | Active — minor |
-| Sable | Ledger's field operative. Quiet, competent, late 20s. Attached to the Book 3 Athel Repository expedition as observer/security. Everything Phelan does appears in her reports — she doesn't hide this, Phelan doesn't object. Field survival, basic ward defence, sending-stone comms back to Ledger. Injured but alive during Cass's Ch18 breach. | Guild observer | B3 Ch06 | Introduced Book 3 |
+| Sable | Ledger's field operative. Quiet, competent, late 20s. **Returning to the site** — she was part of the two-person Cairns forensics team Ledger sent at Week 14 to recover Scout 1's body. Knows the road, knows the perimeter, has walked the Gate's kill radius in silence. Carries Scout 1's field journal in her pack when she meets the team at Pamira's estate in B3 Ch06. Attached to the Book 3 expedition as observer/security. Everything Phelan does appears in her reports — she doesn't hide this, Phelan doesn't object. Field survival, basic ward defence, sending-stone comms back to Ledger. Injured but alive during Cass's Ch18 breach. | Guild observer / returning scout | B3 Ch06 | Introduced Book 3 |
 | Seraphel "Sera" Varrant | Phelan and Mere's unborn child. Conceived late Book 2 / between books. Not born in Book 3 — the pregnancy and preparation ARE the arc. Named based on "Sarah." Nursery planned at Chandler's Row (east-facing, adjacent to the kitchen). | Daughter (in utero) | B3 Ch01 | Expected Book 4+ |
 | Patren | Kimbra's husband. Decent, quiet man she met through work. Not present for Kimbra's Ch04 Chandler's Row arrival but mentioned. Phelan has never met him. | Phelan's stepfather (effectively) | B3 Ch04 (referenced) | Off-page |
 | Margeth ("Mags") | Kimbra's best friend. Referenced in Kimbra's Ch11 letter ("Margeth visited"). May visit Chandler's Row while Kimbra is there. | Phelan's mother's best friend | B3 Ch11 (referenced) | Off-page |
 | Aldric Vane | Warehouse district, east side, near the old grain exchange. Logistics, security. Contact offered to Phelan by Brennan Toor in B2 Ch15 — "Tell him the Wolf sent you." Not yet on-page. | Cairns network node | B2 Ch15 (referenced) | Seeded, not yet on-page |
+| Duke Garrett Holven | Duke of Aldermere (peer duchy to Thorngate). Debt-acquirer across the north for a decade. Recently acquired an unresolved obligation left behind by Pamira's late husband — he has not moved on it, he could, she knows, everyone in the north knows. Named in one private-voice Pamira-at-her-ledger scene in B3 (Ch11 drafter's placement); not on-page in Book 3. Seeded as a Book 4 adversary — if the Compact comes at Phelan through policy, a northern noble coalition with Holven at or near the centre is one plausible lever. | Political rival to Pamira; Book 4 setup | B3 Ch11 (private voice, off-page) | Named but off-page |
 
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