fix(browse): resolve out-of-line text instead of rendering <binary>

Dolt stores text/longtext past a small inline threshold out-of-line,
addressed by a content hash — StringAddrEnc (older writers) or
StringAdaptiveEnc (inline-or-address, current writers). renderCell handled
neither: address-encoded strings fell into the binary-placeholder switch and
rendered "<binary>", while adaptive ones fell through to FormatValue and
rendered the raw address hash. Every long description, close reason, comment
body, and audit-event payload was lost on real databases.

Resolve both through the prolly map's NodeStore (which satisfies
val.ValueStore): GetStringAddr + NewTextStorage().Unwrap for the plain address
case, GetStringAdaptiveValue (string | *TextStorage) for the adaptive case.
Genuine binary/opaque encodings (blob, geometry, json-addr, commit-addr) still
degrade to "<binary>". Fixture grows a >4KB longtext row (folded into C4 so the
commit topology is untouched) and TestRowsResolvesLongText guards it.

browse: read-only doltdb browsing over bare stores

Read-only web-browsing data layer over bare NBS chunk stores, the only
package that reaches into version-fragile dolthub/dolt internals (nbs,
prolly, durable, diff), kept isolated so a module bump re-verifies here.

- open.go: Open/Close per request. Builds the DoltDB from a single
  nbs.NewLocalStore via doltdb.DoltDBFromCS instead of doltdb.LoadDoltDB:
  LoadDoltDB's GenerationalNBS wrapper panics on Close over our bare
  stores in the pinned version (onHeapTableIndex ref count < 0), even on
  a plain open-then-close. The single-store path closes cleanly, gives a
  fresh manifest per request, and is safe alongside the push writer.
- log.go: Branches (+ DefaultBranch pick), Log with topological walk,
  count+start-hash pagination, and commit metadata.
- tables.go: Tables (schema + cheap row count) and Rows via
  durable.ProllyMapFromIndex + prolly IterOrdinalRange, rendered through
  the tuple descriptors; NULLs, binary/out-of-band values and exotic
  encodings degrade to printable placeholders and never panic.
- diff.go: CommitSummary vs first parent (empty root for the initial
  commit) with exact added/removed/modified row counts from
  diff.StatForTableDelta.
- tests: fixture built the production way (WriteEmptyRepo bare store, CLI
  clone/commit/push over a file:// remote); covers branches, log
  pagination/topo order, tables/schema, row pagination incl. empty table,
  commit summaries across the add/insert/modify chain and the initial
  commit, and nonexistent ref/table errors.