Add dialogue progress controls

docs/ARCHITECTURE.md

@@ -59,6 +59,6 @@ Joined officers gate whether `requires_joined` player deployments are loaded at
 
 Inventory and campaign flags are copied from `CampaignState` into `BattleState` when a scenario starts. The pre-battle Chapters overview reads `CampaignState` chapter progress and can load completed or current battles without mutating the save. Briefings preview first-clear rewards and show completed replay rewards as already claimed. The pre-battle Save menu can write the current campaign state to `user://campaign_manual_save.json`, and loading that checkpoint restores it into `user://campaign_save.json` before re-entering the same pending-choice, completion, or current-briefing branch as startup. Pre-battle shop stock comes from the loaded scenario's `shop.items` list plus matching `shop.conditional_items` blocks, with optional finite limits from item entries or `stock` maps. Shop purchases and 50% sell-back are campaign transactions: they update saved gold, unequipped inventory, and finite-stock purchase counts immediately, write the save file, and refresh the already-loaded battle inventory before the player begins the battle. Pre-battle Armory equipment changes use the same equipment rules as battle HUD equipment changes, then immediately save merged roster equipment/stat snapshots and inventory stock. Pre-battle Roster uses scenario `roster.max_units`, `roster.required_officers`, and `roster.required_units` to mark optional player deployments as sortie or reserve; reserve units remain in the candidate list but are excluded from board occupancy, drawing, selection, AI targeting, and living-unit victory checks. Non-controllable player units can act as protected escort targets: enemies can attack them and conditions can reference them, but they are skipped by player selection, Armory, Formation, counterattacks, and campaign roster progression snapshots when `persist_progression` is false. Scenario `ai_target_priority` nudges enemy movement and damage-skill scoring toward important targets such as envoys without overriding defeat bonuses or range checks. Pre-battle Formation uses the loaded scenario's `formation.cells` and only mutates current battle unit positions before battle-begin events fire. Destination victory cells from `unit_reaches_tile` conditions are exposed to the scene for objective overlays and tile info. Movement-triggered `unit_reaches_tile` events receive the unit that just moved, so ambushes and pickup events fire on entry rather than from units already standing on a marker. Briefing data can append matching `briefing.conditional_lines`, and scenario events can use `when.campaign_flags` to branch dialogue, objective changes, item pickups, and reinforcements from saved campaign choices. Consumable use can restore HP or MP or cure matching poison/seal/snare/disarm statuses, and in-battle item use, event pickup grants, plus equipment swaps mutate only the battle copy until victory; defeats and restarts do not spend saved items, keep picked-up items, or preserve in-battle gear changes. Post-battle choices write campaign `flags` only after the result-panel button is pressed; if the player reloads after rewards are saved but before selecting, the pending scenario id restores the victory choice panel without replaying rewards. The next battle button stays locked until the campaign choice save succeeds. Equipment rewards share the same `item_id -> count` inventory stock, cover weapon, armor, and accessory slots, can be equipped from the side HUD before the selected unit moves or acts, and do not appear in the consumable action menu. Named equipment currently uses the same stock model with a presentation-only rarity tag rather than unique item instances. Already completed scenarios can be replayed without granting duplicate rewards, choices, replay inventory consumption, save writes, current-scenario advancement, or finite-stock purchases; pre-battle Shop, Armory, Roster, Formation, and Save are disabled on completed-scenario replays to avoid side effects.
 
-The battle scene owns presentation feedback: briefing and result states use menu BGM, briefing headers combine `CampaignState` chapter ranges, campaign order, and title data with `BattleState` briefing and objective text, active battles use battle BGM, dialogue lines can show optional cached portrait textures or speaker-initial fallback panels in an expanded visual-novel-style panel and can place the portrait on the left or right side of that panel, board units render low-HP warning rings, HP bar color states, and active support/debuff/poison/seal/snare/disarm status pips from battle state fields, hover previews are rendered as target badges from existing `BattleState` forecast APIs, hover unit info shows class, movement type, AGI, movement, range, and equipped gear, equipment option menus show stat/range/effect deltas, result and inventory summaries show named equipment with compact rarity tags, selected area tactics highlight their affected cells, the Threat toggle overlays enemy physical and hostile tactic reach while tile info names threat sources, estimates physical damage, and summarizes hostile tactic damage or status effects against occupied cells, log/result hooks trigger placeholder SFX, support, debuff, poison, seal, snare, disarm, and item pickup effects use distinct floating feedback colors, `BattleState.unit_motion_requested` asks the scene to interpolate a unit's draw position during movement, and `BattleState.combat_feedback_requested` asks the scene to draw transient floating combat text without changing battle rules.
+The battle scene owns presentation feedback: briefing and result states use menu BGM, briefing headers combine `CampaignState` chapter ranges, campaign order, and title data with `BattleState` briefing and objective text, active battles use battle BGM, dialogue lines can show optional cached portrait textures or speaker-initial fallback panels in an expanded visual-novel-style panel, can place the portrait on the left or right side of that panel, and expose progress plus previous-line controls while a sequence is open, board units render low-HP warning rings, HP bar color states, and active support/debuff/poison/seal/snare/disarm status pips from battle state fields, hover previews are rendered as target badges from existing `BattleState` forecast APIs, hover unit info shows class, movement type, AGI, movement, range, and equipped gear, equipment option menus show stat/range/effect deltas, result and inventory summaries show named equipment with compact rarity tags, selected area tactics highlight their affected cells, the Threat toggle overlays enemy physical and hostile tactic reach while tile info names threat sources, estimates physical damage, and summarizes hostile tactic damage or status effects against occupied cells, log/result hooks trigger placeholder SFX, support, debuff, poison, seal, snare, disarm, and item pickup effects use distinct floating feedback colors, `BattleState.unit_motion_requested` asks the scene to interpolate a unit's draw position during movement, and `BattleState.combat_feedback_requested` asks the scene to draw transient floating combat text without changing battle rules.
 
 The `New Campaign` button clears `user://campaign_save.json`, resets campaign state to the first scenario, and reloads the opening briefing.

docs/GODOT_4_6_MIGRATION.md

@@ -62,7 +62,7 @@ powershell -NoProfile -ExecutionPolicy Bypass -File tools\check_godot46_readines
 - Enemy turn advances and AI acts, including damage-aware physical target selection.
 - Victory and defeat panels still appear.
 - Briefings show victory/defeat text plus first-clear reward previews, while post-battle dialogue and post-battle choices still block progression until a choice is saved.
-- Opening and post-battle dialogue can show generated officer portraits from `art/portraits` in the expanded dialogue panel, with speaker initials only used when no portrait is available.
+- Opening and post-battle dialogue can show generated officer portraits from `art/portraits` in the expanded dialogue panel, show sequence progress, allow stepping back to the previous line, and use speaker initials only when no portrait is available.
 - Next battle loads with saved roster, inventory, joined officers, and campaign flags.
 - New Campaign clears the save and returns to the opening scenario.
 

docs/ROADMAP.md

@@ -136,7 +136,7 @@
 - Unit sprites and animations. Board movement now has a short slide animation, and board units show low-HP warning rings plus small status pips for active support, debuff, poison, seal, snare, and disarm effects.
 - Battle effects. First floating combat text now covers damage, recovery, misses, support effects, poison ticks, item pickups, level-ups, and promotions. Hover target preview badges summarize attacks, tactics, and items, and the board can overlay enemy threat ranges with physical damage and hostile tactic hints.
 - Music and sound. Basic placeholder BGM and SFX now play for menus, battle flow, unit actions, tactics, items, and result states.
-- Chapter UI and visual novel scenes. Pre-battle briefing now uses campaign chapter ranges for chapter-aware numbering, has a chapter progress/replay overview, and dialogue lines can choose left or right portrait placement in an expanded portrait dialogue panel.
+- Chapter UI and visual novel scenes. Pre-battle briefing now uses campaign chapter ranges for chapter-aware numbering, has a chapter progress/replay overview, and dialogue lines can choose left or right portrait placement in an expanded portrait dialogue panel with progress and previous-line controls.
 
 ## Milestone 6: Content Expansion