v0.19.1 — base-stage anchors + chromatic flow palette

UI

• Project flow prepends cry → plan → tdd base-stage anchors ahead of the crafter/ship chain. Each anchor starts idle and highlights once its latest session completes; completed anchors link to the matching /sessions page.
• Each base stage wears its own signature hue — cry violet, plan azure, tdd mint — so the pipeline reads as a chromatic arc instead of a flat stack of identical green cards. Disabled anchors keep a subtle wash of their hue.
• Session flow derives the node accent from (agent × skill) instead of just the agent. Three invocations of the same agent with different skills now render as three distinct shades of the same family.