Port authored Age features and Star Fissures to 26.3 beta

Advance to 1.0.1.54-beta.1 after player validation. Port material, vegetation, lake, terrain-volume, crystal, Dense Ores and fissure features with saved plans. Update beta documentation and release notes.

Refs #98, #104

ports/mc263/README.md

@@ -211,6 +211,146 @@ first surface-feature path; unsupported combinations stay in the Binder.
 Random feature selection, unpaired materials, duplicate feature pages, and
 instability scoring remain future port steps.
 
+The local `1.0.1.42-beta.1` follow-up lets a Rocks page choose a deterministic
+full-block material when no Block page precedes it. Repeated Rocks pages now
+add independent placement attempts (up to 32) instead of being rejected. The
+ordered material choices are frozen in the Age index and restored after a
+restart; old single-material beta Ages still load. An explicit Block page
+must still directly precede the Rocks page it modifies. Most other feature
+pages and material-feature pairings remain unported.
+
+The local `1.0.1.43-beta.1` slice replaces the temporary 3×3 Rocks piles
+with Minecraft 26.3's forest-rock block-blob feature and its placement rules,
+matching the 1.21.1 Age feature path more closely. The selected material and
+repeat count still come from the frozen Age plan. Only newly generated chunks
+use the new rock shape; previously generated chunks remain unchanged.
+
+The local `1.0.1.44-beta.1` slice ports ordered Flowers, Trees, and Huge
+Trees pages to surface Ages. Their 26.3 vanilla placed features run after
+biome decoration, with the Age's own seed; repeated pages make independent
+placement attempts. Cave/Void terrain and cave/Nether/End biome pools are
+not treated as surface vegetation. The feature plan survives server restart;
+already generated chunks do not gain new decoration.
+
+The local `1.0.1.45-beta.1` slice ports the Dungeons page for Standard,
+Amplified, and Island noise terrain. It uses the 1.21.1 placement definition
+(eight monster-room attempts per page per chunk across the build height),
+stores repeat count with the Age, and rejects Dungeons pages on Flat, Void,
+or Cave terrain. New chunks only; existing chunks are not regenerated.
+
+The local `1.0.1.46-beta.1` slice adds Surface Lakes, Deep Lakes, and Small
+Lakes on surface noise terrain. A Fluid page immediately before a lake page
+selects its fluid. Unmodified pages choose a seeded fluid from the same source-
+fluid pool exposed in Creative, with repeated choices and their order saved
+with the Age. Surface/Small Lakes retain the 1.21.1 one-in-twelve attempt rule;
+Deep Lakes retain vanilla underground placement. These pages currently require
+Standard, Amplified, or Island terrain. Existing chunks do not redecorate.
+
+The local `1.0.1.47-beta.1` slice adds authored Floating Islands alongside
+Standard, Amplified, Island, Flat, and Void terrain. A preceding Block page
+sets the island core material; otherwise each occurrence resolves a seeded
+material from the full-block pool. The 1.21.1 shape, high altitude, rarity,
+and biome-dependent grass/dirt cap are retained. Repeated pages use independent
+island seeds. Cave terrain remains unsupported for this feature.
+
+26.3 combines base noise, surface, and cave carving in one terrain operation.
+Floating Islands run after that operation and before decoration, so the added
+islands are not cut by the base terrain's carvers. The saved feature plan is
+used again after restart and for new chunks; existing chunks keep their blocks.
+
+The local `1.0.1.48-beta.1` slice adds authored Tendrils on every terrain
+type, including Cave and Void. A preceding Block page selects the material;
+unmodified occurrences resolve seeded materials from the full-block pool.
+Repeated pages use independent paths, with up to 32 occurrences per feature.
+Mixed Floating Islands/Tendrils retain their authored order in the saved plan.
+
+Tendrils retain the 1.21.1 branching path algorithm, source rates, and vertical
+distribution concentrated below Y=128. They can replace existing terrain while
+preserving bedrock. As with Floating Islands, they run after 26.3's combined
+terrain operation and before decoration. Build checks are automated; in-game
+generation, appearance, and restart validation are handed to the player.
+
+The local `1.0.1.49-beta.1` slice adds the Skylands feature page. Its seeded
+seven-octave filter removes base terrain at/below a varying cutoff near Y=76
+and removes liquid above it, preserving the upper solid terrain. It accepts
+all terrain types and no Block modifier. On low Flat terrain this removes
+the base layers; on Void it leaves the empty base unchanged.
+
+The filter runs once before authored Floating Islands and Tendrils, matching
+1.21.1; duplicate Skylands pages do not compound the filter. Its flag is saved
+with the terrain-feature plan. Existing chunks are unchanged. Try Amplified
+terrain for a clear visual check; generation and restart validation are manual.
+
+The local `1.0.1.50-beta.1` slice ports Spheres and Spikes using the 1.21.1
+generation algorithms. Spheres add solid nodes on all terrain types, including
+Cave and Void, while preserving bedrock. Spikes require solid surface terrain:
+Standard, Amplified, Island, or Flat. Their circular footprint stays in one
+chunk and must have solid ground beneath every column.
+
+Each page accepts a preceding Block material or resolves a seeded random
+material when unmodified. Repeated pages have independent placement seeds,
+up to 32 per feature. Spheres run during terrain construction, after Skylands;
+Spikes run after biome decoration. Both use the existing saved solid-feature
+plan. New chunks only; in-game appearance and restart checks remain manual.
+
+The local `1.0.1.51-beta.1` slice ports Obelisks. It preserves the 1.21.1
+one-in-128 candidate chance per chunk/occurrence, 4×4 plinth, and 2×2 shaft
+extending 12 blocks above it. Placement requires dry, sturdy ground across
+the base, at most two blocks of surface variation, and clear/replaceable
+space for the complete structure. The footprint stays within its chunk.
+
+Obelisks support Standard, Amplified, Island, and Flat terrain. A preceding
+Block page sets their material; otherwise a seeded full-block material is
+selected. Repeated pages make independent attempts, up to 32 occurrences.
+Spikes and Obelisks share surface-stage classification and preserve their
+authored order within that stage. World and restart validation are manual.
+
+The local `1.0.1.52-beta.1` slice ports Crystal Formations using the 1.21.1
+surface-mound algorithm and the existing blue crystal blocks. Each occurrence
+has a one-in-fifteen candidate chance per chunk; suitable dry, nearly level
+ground produces a 3×3 mound with budding crystal and occasional small buds.
+The existing budding blocks continue growing crystals through random ticks.
+
+Crystal Formations accepts Standard, Amplified, Island, and Flat terrain,
+but not Cave/Void terrain or Block/Fluid modifiers. Up to 32 repeated pages
+make independent attempts. The ordered feature plan survives restart, and
+only newly generated chunks receive formations. For a quick manual test,
+bind a Flat/Plains Age with several Crystal Formations pages, inspect the
+blue mounds and bud growth, then revisit after restarting the world.
+
+The local `1.0.1.53-beta.1` slice ports Dense Ores. Each page replays eligible
+ore placements from the Age's actual biomes, preserving their height ranges,
+replacement rules, and biome filters. Vanilla and modded ore features are
+recognized by their ore targets; custom placements can opt in through the
+`rivencraft:dense_ores` placed-feature tag, just as in 1.21.1.
+
+Up to 32 pages add independent passes on Standard, Amplified, Island, or Cave
+terrain. Flat/Void and Block/Fluid modifiers are unsupported; an explicitly
+authored biome pool must contain at least one ore-producing biome. The count
+survives restart. Only new chunks gain extra ore, and this slice does not yet
+port the later instability system or random-Age feature selection.
+
+For manual validation, create a Standard/Plains Age with several Dense Ores
+pages and inspect underground ore abundance, then restart and explore more
+chunks. A Cave Age with a Nether biome can check Nether ore placements too.
+
+The local `1.0.1.54-beta.1` slice ports the Star Fissures page. On first book/
+operator arrival, it carves the 1.21.1 Legacy-shaped rift near the arrival chunk
+and places a starfield portal at the dimension's minimum Y. Cave terrain keeps
+its bedrock roof. All terrain types are supported; repeated pages still create
+one fissure, and Block/Fluid modifiers are not accepted.
+
+The first arrival and completed generation are saved per Age, so revisits and
+restarts do not recarve the rift. Touching its bottom returns entities to a safe
+location near the shared Overworld spawn, not a bed, with the original fissure
+sound. The portal is unobtainable and inert in the Overworld. Random-Age feature
+selection remains later work; author a Star Fissures page to test this slice.
+
+For manual validation, create a Flat/Plains Age with Star Fissures. Look near
+the arrival point (generally east/south), descend through the rift, and touch
+the starfield to return. Re-enter after restarting; check that the same fissure
+and its portal still work. A Cave Age checks that carving leaves the roof intact.
+
 From the repository root:
 
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