docs(wiki): roadmap-open-core.md's phase table is one phase behind roadmap.md, so four rows name the wrong phase

[amondnet]

What

wiki/deep-dive/roadmap-open-core.md's "Phase status at a glance" table (L17-L26) is one phase
behind docs/roadmap.md. Phase 5 — Content-aware PII / DLP was inserted into the roadmap and the
wiki table never gained a row, so every row from "4" down names the wrong phase and cites the wrong
range.

Found while resolving the #253 ledger: docs/roadmap.md#L93-L100 is one of that issue's anchors.
The issue filed it as an authoring off-by-one — "the range opens on the blank line after a heading"
— but verifying it rather than adding 1 shows it is not. Adding 1 lands on a --- rule between two
sections, and the section the row is actually about moved 60 lines further down.

Verified against main @ bf9b057

docs/roadmap.md headings: Phase 0 L23 · 1 L34 · 2 L51 · 3 L65 · 4 L96 · 5 — Content-aware PII /
DLP L121 · 6 — Isolation modes L154 · 7 — Team / control plane L231 · 8 — Hosted SaaS &
intelligence L243.

Wiki row	Cited as	Actually there	The section it means
L23 "4 — Verdicts, audit & dashboard"	roadmap.md:81-101	tail of Phase 3 + head of Phase 4	Phase 4, roadmap.md:96-117
L24 "5 — Isolation modes"	roadmap.md:93-100	blank line, ---, and the Phase 4 heading	Phase 6, roadmap.md:154-166
L25 "6 — Team / control plane"	roadmap.md:104-112	Phase 4's dashboard checklist	Phase 7, roadmap.md:231-241
L26 "7 — Hosted SaaS & intelligence"	roadmap.md:116-122	Phase 4 exit criteria + Phase 5 heading	Phase 8, roadmap.md:243-
—	—	—	no row at all for Phase 5 — Content-aware PII / DLP (roadmap.md:121-152), which is largely shipped

The status cell on the Isolation-modes row is also stale: it reads
hardened run on Linux · macOS, join planned, where roadmap.md:157-158 marks both Linux and
macOS [x] (Seatbelt under sandbox-exec, ADR-0005).

Three of these four rows start on a content line, so scripts/check-wiki-source-anchors.ts cannot
see them — they are an instance of the "lower bound" caveat #253 records about the checker.

Why it matters

The row is the reader's index into the roadmap: they click "5 — Isolation modes" and land on the
Phase 4 heading. Renumbering one row in isolation would put two "6"s in the table, which is why
this is one change to the table rather than a row-by-row fix.

Scope

Renumber L19-L26 against docs/roadmap.md as it is now, add the missing Phase 5 row, re-anchor
each Source cell, and correct the Isolation-modes status. The docs/roadmap.md#L93-L100 entry in
the TRACKED ledger of scripts/check-wiki-source-anchors.ts is attributed to this issue; drop it
when the row is repointed.