Feat/dynamic soc at start

[BelhsanHmida]

Description

• Use state-of-charge as a fallback source for soc-at-start in storage scheduling
• Support inferring start SoC from either recent sensor beliefs or a provided SoC time series
• Raise an error when a configured state-of-charge source is stale or missing near schedule start
• Keep the existing fallback behavior afterwards and remove the CLI requirement for explicit --soc-at-start
• Add test coverage
• Added changelog item in documentation/changelog.rst

Look & Feel

No UI changes.

API / CLI behavior change:

• Storage scheduling now works without explicit soc-at-start when state-of-charge is configured and has a recent value
• Storage scheduling now fails fast when state-of-charge is configured but stale / missing around schedule start

How to test

Run:

• pytest -q flexmeasures/data/models/planning/tests/test_storage.py -k "state_of_charge or soc_at_start"
• pytest -q flexmeasures/api/v3_0/tests/test_sensor_schedules_fresh_db.py -k "state_of_charge_sensor_for_soc_at_start"
• pytest -q flexmeasures/cli/tests/test_data_add_fresh_db.py -k "state_of_charge_sensor_for_soc_at_start"

Manual checks:

• Trigger a storage schedule without soc-at-start but with a recent state-of-charge sensor value and confirm scheduling succeeds
• Repeat with only a stale SoC value and confirm scheduling errors instead of silently falling back

Related Items

closes #1895

Sign-off

• I agree to contribute to the project under Apache 2 License.
• To the best of my knowledge, the proposed patch is not based on code under GPL or other license that is incompatible with FlexMeasures

[read-the-docs-community]

Documentation build overview

📚 flexmeasures | 🛠️ Build #31821934 | 📁 Comparing 0cfff19 against latest (4c06249)

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Show files changed (5 files in total): 📝 5 modified | ➕ 0 added | ➖ 0 deleted

File	Status
_autodoc/STATE_OF_CHARGE.html	📝 modified
_autosummary/flexmeasures.data.models.planning.storage.html	📝 modified
api/v3_0.html	📝 modified
features/scheduling.html	📝 modified
tut/forecasting_scheduling.html	📝 modified